well, i'm more a fan of old fashioned tuning... but it's freakin expencive, replacing the cam shafts, exhaust, cylinder heads, filters .. and the list goes on and on and on..
with the turbos, you just get a large intercooler and a custom map and you get a much bigger boost in performance comparing to how much you invest. though, again you get a lot more if you replace the cylinder heads and cam shafts .. and the exhaust :P
haha.. it's a complete money sinkhole :D