Taking the plunge soon. Subscribing to the adage: Buy once, cry once. Whittling down options in a new higher end optic, and a ZCO caught my eye. Anyone own one or have experience with Zero Compromise? Scares the bejeezers outta me to spend that much on good glass, but know quality glass is king--especially for my old peepers. Also in the mix are Leup Mk5HD, Steiner T5Xi, March FX, and Kahles 624i. Would love a TT but not sure I could get that past The Wife without a hot tongue and a cold shoulder. Any advice will be greatly appreciated.
Out of the scopes you mentioned, I will give you my experience. I either own/owned, or shot behind several examples of them.
First, with the mention of the Kahles K624i and March FX (I assume the 4.5-28×56), I will also assume the Steiner T5Xi would be the 5-25×56, the Leupold Mk5HD 5-25×56 and the ZCO 5-27×56?
If you are talking about the 3-15×50 to 4-20×50 range, same advice will apply, but I will give some other options to consider as well in the true ALPHA level glass choices.
Hands down, 1000% best scope in your list is the ZCO. Nothing else even compares, or in the same ballpark. Practically not even in the same sport. Like comparing T-ball to high school ball to the Major League. It is that much better than the rest. I own two ZCOs. And have shot behind several others. The ONLY downfall compared to some of the others is the added weight.
Glass is insane, DOF, color, contrast, clarity, pop, edge to edge, etc. Turrets are amazingly tactile and audible, maybe even better than TT, repaetable, tracks true, RTZ has never failed in mine, mag and parallax rings are perfect tension. Locking turrets are just the right tension. Good reticles available in the MPCT1 for an uncluttered, or MPCT2 & MPCT3 if you want a Christmas Tree style. I have an MPCT1 and an MPCT2. I use the ARC M10 36mm rings with mine. Amazing rings, and super easy to set up.
Steiner T5Xi. I had one of the first run T5Xi 5-25×56 @ $2k. It was comparable to my $1400 SWFA 5-20×50HD. But much more frustrating. I had to send mine back for repairs 3 times and it never got resolved to my satisfaction, and this was before I got any of the real top tier scopes to compare it to. So it really put a bad taste in my mouth for the scope. Glass was just average. My parallax was terrible. I spent 2+ hours to get the diopter and parallax "close". I could never get the parallax completely out and have the target image clear. Mag ring had huge slop in it. Turrets are cool and the 2nd rotation indicator is cool, and felt good and audible, but a touch less tactile than other turrets. The SCR reticle in mine was medium grey, not black like every other etched reticle is. This never got fixed. I think there is a reason you don't see a lot of these out in the wild. I think the line was a flop from the beginning, and word and reviews spread, reallybputting a damper on referrals and sales. I have not shot behind another one to compare. I would avoid unless you can find a used one for $1k-ish. I think more than that and the price point exceeds the scope. Other will disagree. But no way was mine a $2k scope.
March FX 4.5-28×52. These are better than the March F 3-24×52 in my opinion. I owned one of the 3-24 for a while. The huge draw with that one was the 24oz and the 8x erector. March got away from both with a 29oz scope and 5.5x erector. This actually helps the scopes performance however, along with the "High Master" glass. Eye box is better, parallax is far more forgiving. Glass is noticeably better, but still not up with the big boys like ZCO, TT, S&B, Minox ZP5, Hensoldt class. Turrets are very good, track perfectly, and tactile and audible. Reticle designs are OK to good. FOV with the new WA eye piece is amazing. The 4.5x appears as wide as other 3x. Length is nice too. It would probably be a close choice for 2nd with the Kahles, each beat the other in certain areas.
Kahles would more than likely be my second choice. But, I would look for a used one in the $2k-2400 price range. I don't think they carry their weight in the $3200+ price range.
I had a K624i for years. It replaced my T5Xi, and I was ecstatic with the upgrade. Even at +$1200 more at the time.
The K624i is known for the wide FOV at 6x, comparable to most 5x FOV. I had the SKMR reticle, and absolutely loved it. One of my all-time favorite uncluttered reticles. Turrets were excellent, tactile and audible, tracking was perfect. Glass was very good, on par with NF ATACR glass. A common complaint is the CA (chromatic abberation), or seeing a purple/yellow haze around high contrast black/white. The only reason I got ride of mine was it was on my daughter's 15.5# 6.5SLR, and when we shot the barrel out at 2800 rounds, I completely rebuilt it and shed 5#. The scope change was only due to weight reduction. Parallax is very forgiving, as well as the eye box. But parallax placement takes getting used to.
Leupold Mark 5HD. I don't own one, but Inhave shot behind several. I like the "zero stop/turret lock" button. Turrets are good. Leupold has a reputation for tracking issues, so it is a no-go for me. I don't like the TMR/TMOA reticle. But there are some I do like, the PR1 & PR2 Mil. Glass is OK. Not on par with the top for sure, but price is not in the same ballpark either. Seems like my buddy is always saying his drops are off at 500+ with several rifles wearing Mark 5HDs, which leads me to believe tracking is not 100%.
If you are seriously looking in the $3500+ price range, there would be a few other scopes I would suggest looking at as well. But, I still think the ZCO beats them.
If weight is a concern more than a 25-28x top end, the Tangent Theta TT315M or TT315H at 3-15×50 & 27oz are amazing. I own 4 of the TT315M. I shoot them out to 1500+ monthly. Same glass as the P lines, turrets are insane. But are "only" dual turn 6MIL, so 12MIL of elevation usable adjustment. The 5-25×56 TT525P is in a whole other price range. And the pinnacle of scopes.
Their are a few different S&B PMII lines to consider. You can find them used at significant discounts too. S&B is to be considered the "Gold Standard" of scopes, being the OG for top tier for decades. Even being dated designs and glass, they still rank right up there with the "best".
5-25×56 (in a DT, or MTC/LT version)
If you are looking for smaller/lighter and in the 20x top end, the 3-20×50Ultra Short and 5-20×50 Ultra Short are amazing scopes. I own one of each. But, unless you go with a really high mounting solution, they really only fit on a short action.
Then there is the 3.5-27×56 Hi-Power, but they are in the TT525P+ price range.
The Kahles K525i and K318i differ a bit from the K624i. Glass is better, but for some reason, FOV was narrowed. I have a K318i currently on a .260AI, and love it.
The Minox ZP5 line (3-15×50 & 5-25×56) are very close to the S&B PMII and barely behind the ZCO lines. They are not as popular, but glass is excellent. Some complain about the 2nd rotation gets stiff as it transfers over, and some complained of a stiff mag ring. Minor inconveniences on a great scope. They rarely come up used for a reason.
Then, there is the Hensoldt ZF 3.6-26×56. $8k. Yeah, I still don't have one of these either.
Premier Heritage are the old Tangent Theta. While discontinued and hard to suggest because of this, I have 2 (a Light Heritage 3-15×50 and a Heritage 5-25×56) that compete with Tangent, and get passed around my rifles and test rifles like a 3rd string cheerleader with self-esteem issues and a daddy complex. And keep on begging for more. I am currently running the 5-25×56 on my 25 Creed, but it has ridden on everything from a 6 Creed to a .300RUM. My 3-15 Light Heritage sits on my AR, but is my go-to for mounting on rifles that need a load development done and don't have their own scope yet.