I've been addicted to Glock Talk's Caliber Corner forum for the past month or so. It's tough to wade through all the rhetoric and BS, but there are few posters who are very knowledgeable and have cited empirical testing that makes me believe the Ranger T is the round of choice for any of the common service calibers.
I would prefer the 147 grain Ranger T over the 127 +P+. The tests I've read seem to infer that the performance of both rounds is very similar, with the 147 grain having significantly less muzzle blast and recoil.
I have also heard nothing but good things about the source that McOz quotes above, although I personally have never bought any from him.
I just read on another thread about a website that has the best price on Ranger T 147gr - $108 for 500 rounds. Sounds pretty insane to me, but I am thinking about doing it. DISCLAIMER: I have NEVER bought anything from this store so BUYER BEWARE -
http://store.yahoo.com/expresspolicesupply/w100.html
Jeff