I've got a altitude, from before it had that moniker and was sporting the old action. I've got nothing but good things to say about it. The rifle shoots significantly better than I can shoot it. Robert and team at APR are good people and will do anything to make you happy with your rifle. Be warned though, they will try hard to lead you away from things that don't seem to work 100% of the time for builds they make.
Heck, if you ask, they will let you know what day/time they're gonna chamber your rifle and let you witness the barrel being indicated in and machined.
When you call, you'll probably get Garrett or John (front desk guys). They're very knowledgeable about most of the standard questions customers ask, but if you ask for Robert he will call you back to answer any of the more technical questions you have.
PS. Ask about the reamer... they usually have several. 1 Sammi and a couple that are set up for specific applications/bullets.