I have all 3 of those you listed (a 4-16x50 PST FFP) and a 3-12x42 and 4-16x50 Nikons. All the Nikons have side focus.
I'm not going to complain about my Nikons, but after getting to know the FFP vortex I will not be buying a SFP scope again. Nor will I buy anything that does not have at least target style turrets (they don't need to be 2" long).
How you use them can be a big factor in whether the FFP is valuable to you or not. Most of the time I am shooting at coyotes and most of the time they are moving, so being able to see 2, 4 or 6 moa of hold for drop or wind right on the reticle (and knowing it is accurate at any magnification - if I can see it) can be very helpful. There are plenty times I have not had the chance to even adjust magnification before it was all over.
If you have more time to contemplate then you may not appreciate the benefit of the FFP reticle. On the 4-16x50 it is a $200 option on the 6-24 it is a $100 option. I don't know if the "regular" PST's are illuminated too.
You might consider the M223 3-12x42 (the non BDC rapid turret version) Nikon M-223 3-12x42SF Riflescope Nicoplex Reticle Matte with Rapid Action Turret - Natchez Shooters Supplies
Natchess has them for $450.
Optics Planet has the M223 4-16x42 for just another $20 more also with turrets.
Nikon M-223 4-16x42mm Rifle Scope FREE S&H 8493, 8492. Nikon Rifle Scopes.
These models were at least $200-300 more when I got my Monarchs or I would have bought them back then.