I've used it for over a year now. I agree it's not entirely for beginners, but it's not terribly out of range either. I like that's it's mobile only personally, I don't want a server. I'm a fan of on device backups that sync with my NAS, but I can see the appeal if you use multiple devices for some reason.

One thing that is nice in an odd way is how it handles custom exercises. You can track similar things differently to really hone in on progress. For example, I'll have a leg day where leg extensions are first in the workout (I'll call machine leg extensions) and on my second leg day it comes after squats where I'm less fresh (so I'll call it machine leg extension 2) that way I can track progress on them separately since my performance is different based on exercise order.

The UI is nice, the graphing is nice. Honestly the most missing feature (as of two weeks ago at least) is either pre-loading my last weeks numbers into the current weeks exercise list so I know what numbers my goals for that day are. I usually just flip between the program and the history to keep track. "Ok last week I did 55 for 7, let's try to get 8 or 9 this time". It's not bad, but it would be nice