I'm going through a similar decision myself. For me, the hardest decision is whether I want to be limited to a SFP ballistic reticle or a FFP mil style reticle. With the SFP BR you always have to be at max magnification and use Swaro's calculator to figure out impact for your particular rounds. With the FFP mil reticle you can be at any magnification and if you know the DOPE for your round it will not matter what magnification you're on (except for lower magnifications where FFP reticles tend to disappear if they're too light).
I know that ballistic reticles can be a point of contention between many, but I like them for the simple fact of how quick they can be in the field. For instance, you spot the trophy elk off in the distance, grab your rangefinder and find that he is 557 yards away, with a ballistic or mil reticle you probably already have your dope on a chart hanging off your rifle and you quickly ascertain that you need to use the 6th line down, you raise your rifle and take the shot accounting for wind. Once you get good at this you can probably get the shot off in a few seconds. Now, same scenario but you don't have a ballistic or mil reticle, now you have to figure out how many clicks to get your turret to 557 yards, and then you have to account for wind and click appropriately there, then you can take the shot. My guess is this is going to take a few seconds longer at least to dial in. Dialing in is great when you have the time, but often you don't have the time in the field and those seconds can mean the difference between getting the trophy or watching him walk back into the thick.
Optically I'm not sure how much difference as both use fantastic German glass with excellent coatings. Premier is built in the USA. The Swaro gets you an extra 3x at the top which might be good for ELR, but the more I research it seems that 15x with good glass will also get the job done.
These are my thoughts, I'm sure others have some different ideas