This is a 2 part question in a way. First off, the gear setup that you would be putting in (the Gforce) comes in 2 different styles, those being helical (sp?) cut which is like stock gear and they taper almost to a point with each tooth. Then you've got the straight cut gears, which to my understanding (could be wrong here) require a Pro Shift treatment, and after that you have to be in high RPMs to get them into gear. Again, i'm not sure on that second part but i know they're straight cut gears.
Anyways, the gear ratios of both tooth styles are different than that of the stock T5 so it will shift differently, and my guess would be a tad harder to get into gear, similar to a Tremec TKO or 3550. The best thing about a Gforce T5 is it just bolts right up and there's no need for a special bell housing like you get with a 3550/TKO.
rockin rick...not sure if that was an attempt at a joke or sarcasm...lol, yes there's a clutch just like any other 5 speed if that's what you mean. The difference lies in the gears and input shaft, since the case is a stock T5 case.