I was involved in some research on "live high train low" a number of years ago ( details if you're really interested ). Stray-Gunderson and Levine felt that exposure to 8k+ elevation for at least 8 hrs a day kept your EPO level high enough to increase red blood cell counts. The ideal is 16 hrs a day at elevation, and <10 hrs has reduced impact. Also, the effect plateaued after about 3-4 weeks of doing so. I've tried the live high train low geographically (sleep in Park City at 8k, train in Salt Lake City at 4k) and hypobaric chambers (the Portland one mentioned here and 2 others), and hypobaric was definitely less intrusive on the rest of my life (excluding my girlfriend's aversion to it).
Did it work? My Vo2 max scores went from 77 to 83 in a 4 week period under the study above, but there's no way to really say how much was due to live high train low versus training under ideal conditions with 25 other athletes. Yeah, I think there's definitely something to it, but you'll probably only notice it at the extremes of effort levels. Would it be beneficial to climbing? Maybe, but probably more mental than anything since it's rare you're at or near max Vo2.
My two cents.