Watercoolers are often just as loud if not more loud than air coolers, Also the H50/H70 had well documented leaking issues, for a watercooler in that price range I'd catch the H60 on a rebate for 54.99, thats what I got mine for.
Also for low end water coolers you can get just as much performance out of a mid-high end air cooler like a Hyper Evo 212, Thermaltake Frio, or if you want to shell out the big bucks a Noctua NH-D14 for 75 bucks.
I'd reccomend the Hyper Evo 212, you dont need anything more for anything that's not a hex core Extreme.
ive had a few friends use the h50s and h70s no problems there.
also a closed in water system is more silent than an air cooler, depending on what u get :P
Update - I went out and bought the H60 from Microcenter. It has reduced my temp by 15-20 degrees while playing battlefield! The only noise I hear is the fan that is attached to the radiator which is basically a chassis fan. There has been no increase in noise.
For Intel CPUs at least I wouldn't worry until you're in the early 90s.
good nah, u dont wanna hit higher than 70-72 load imo, thats the safe zone.