Great to hear from you here.
I tried out rbenv this week and have decided to say goodbye to it. The
rbenv rehash business is just a time killer for this kind of stuff, just logging on to my machine took 10 seconds due to rbenv business.
Instead I am going with chruby which is lightning fast and supports enough rubies to keep me happy.
I am also keeping all the builds around, I seem to have enough storage for it. When benching Discourse I am able to bundle --standalone which saves a lot on storage (although I do need to do some magic to allow for rubygems changes)
My current bench setup is using an oldish desktop I have, completely dedicated. Its an i7-960 with an ssd, slower than my current desktop but perfectly decent.
I had to spend a fair amount of time with cpufrequtil to get the clock to run at a consistent rate without it benching is rather inconsistent.