Hmmm... well I'm a little biased on which car I like better...

But in a straight line;
stock for stock: GS-T
Equal amounts of money into each: GS-T

Handling: I've never owned an Integra so I can't say for sure. I did own two CRX HFs with B16 swaps while I was in college. Those cars with springs/shocks stut bars and 215/40/16 tires didn't handle as well as my spyder did stock with a good tire(G-Force on stock 16 wheels), granted the spyder GS-T does have a stiffer sub-frame than the hard top GS-T. I can't honestly compair the integra as far as handling though.

I think the initial question was which would win in a straight line and the GS-T would dominate.

As for the "Damn i have to tune again" sub topic. That comment comes from the Apexi SAFC users only(which are most DSMers). Maf-Translator (me), VPC, DSMLink, AEM EMS, and standalone users don't have this problem unless they make large changes like turbo swaps.
I don't feel like explaining the reasons but if any one here knows the reasons behind the Kv style MAS + SAFC tps/rpm point tuning method needing adjustment with different temperature(density hint hint) air, feel free to school some people and squash some reliability myths.