I’ve been pondering this at the moment, mainly because my wife wants to commandeer my current hardtail and its a good excuse to n+1!
I’m fairly keen on the stif but theyre out of stock and stif themselves cant get a straight answer on delivery from the factory.
As far as I can see the stif has almost identical geometry to the P7 apart from 10mm less travel. Its definatley in the trail/ hardcore side of things.
The soul definitely has more conservative geometry – longer chainstays, shorter and steeper
My viewing of the cotics was that the solaris was just the 29er version of the soul and so not that hardcore. Hopefully ill get to demo a soul this weekend so I can report back if it helps
The pace r127 has good reviews and is similar to the soul in attitude I think.
Also worth looking at the 2015 or later transition trans am which you might find a bargain on as they’ve stopped making them now. That’s what I have currently and its a great bike. Not the lightest frame but rides great for a blast round the woods or a 3 hour ride. I’m only looking around as my wife wants mine.