I found that you can get out of it what *you* want. Just like a spinning class, the instructor will yell and scream for you to go faster stronger harder, but if you can't, then don't and don't get yourself hurt just because someone told you.
Since the workout description is usually on the board at the beginning of the class, I took the coach aside and would ask for modifications on things that I had limited range on. Then I didn't have to interrupt the flow of the class during the WOD.
I loved crossfit and wish I could continue. I was never bored with the workouts and got really strong really quickly. Unfortunately, the schedule didn't fit well with mine and it was pretty pricey per month.
-- gnat!
Windsor: 2010 S-Works Ruby
Pantysgawn: 2011 S-Works Stumpjumper 29er
Whiz!: 2013 S-Works Crux (Singlespeed)
Boucheron: 2009 S-Works Tricross
Haloumi: 2013 Tern P7i
Kraft: 2009 Singlecross
Gouda: 2005 Electra Betty
Roquefort: 1974 Stella SX-73