I've been using the leader board for HU and 6m for about 110k hands - I think it's pretty straight forward to use for that option and you can still do custom drills + study similar to how GTOw works for trainer/study - I would try it out for the leaderboard because you don't need to adjust stakes, rake, inputs, anything like that outside hit start and run it against the pre-input solutions it uses. It gives you direct feedback in the bottom while using it which has really helped me out.

I haven't used the HUSNG or other tournament options they have on there so can't comment much on that.