Have you ridden both bikes? That will probably be the biggest factor, is how well you fit and how well the bike handles with you on it. Even though the Performance page seems to have some contradictions as to the drivetrain spec (the description says SX5 24 speed, but the specs say SX5 and XT 27 speed) so I am not sure what exactly is going on with that (SX5 shifters and XT derailleur are not compatible by the way). Either way, both are solid bikes. The Iron Horse has a little nicer fork, but that Tora is very good and worked well for me on my old hardtail.
If you have not ridden both bikes, go ahead and check them out in person. I don't know how the Performance shops are in your neck of the woods, but here in central Texas they aren't the greatest as far as their level of expertise. You may (or may not) receive better service from a smaller, privately owned shop. Scope it out and see what vibe you get.
I think either bike you choose will make for a great XC hardtail. I used to work at a shop that was a Kona and Iron Horse dealer and they both make awesome bikes. I was more partial to the Kona geometry, but that is why you need to ride both bikes.
Good luck and have fun.