I'm glad this topic got brought up... I've been talking to a guy at a speed shopt about what is better. He said he's leary of puting any kind of forced induction on an engine w/ the LS2's high compression ratio.
Find another shop. Times have changed, engine controls have gotten better, etc. if they still think that, they are stuck in the stone age

. There are several people running boosted LS2's and quite a few of us running 10 psi +. Yes, it is *slightly* harder to tune than boosting a low compression motor, but find a boost compression calculator and you will see that even 10 psi on an 10.9:1 motor is 18.31:1- lower overall static compression than the say 21 psi used on a low compression 8.5:1 turbo motor- 20.64:1 at sea level. Check out this link and play around with some numbers-
http://www.rbracing-rsr.com/compression.htm , pretty nice tool I have used with several turbo motors just playing around. Reliability is all in the intercooling and tune.
A turbo will ultimately be faster with a good tune, setup, etc. but I do think the procharger with it's "softer" hit and linear power curve will probably be easier on the motor. I have a Procharger on mine only because I didn't like the pricing on the turbo kits or the quality of the cheaper ones, I'll just build my own when the time comes and sell the blower.
Joe