Lots of different opinions will come out, no doubt. It also depends on conditions, if you have someone spotting for you or you have to do it yourself, etc. It doesn't take a lot of mag to SHOOT a target at a mile, but if you're self-spotting you need more mag, and most importantly, excellent resolution.
For me, I'm self-spotting most of the time. I mostly have everything set on 25X at that distance, even the NF 7-35 and SB 6-36. The SB 5-25s also stay on 25X. All of them have excellent resolution, so it works pretty well for me. A cheaper scope with similar mag but poor resolution would not be up to the task.
This is just what works for me, in the conditions I shoot in (Southeast, green hayfields).
I've kind of come to the opinion that the lower-cost end of the "buy once, cry once" ELR optics is the NF 7-35 ATACR. Going up in cost from there are the SBs, ZCOs, and TTs (and a few others), all very capable and with even better glass and other features, but the NF at least performs at a level that it could never be blamed for holding you back, costing you a target, etc. It's a great place to start if cost is a concern (still expensive, but somewhat, to much less so than the others). It is very popular in ELR comps, and seems to hold its own if match results are any indication. That said, I still prefer my SBs, but they cost more, and the NF has performed well enough I don't see it as a handicap.