In order to achieve a fast launch you need two things: 1) to be in the power band, meaning you do need some revs ~3200 should do the trick 2) traction, you don't want to give so much power the wheels break loose.
Our cars make good high-end power, meaning that in the top of the rev range (5500rpm+) the car achieves its top HP figures while Torque peaks out a bit earlier and flattens out (find a dyno sheet on here and you'll see what i mean). So you don't really want to shift until you have hit the rev limiter since the power doesn't really drop off until about then.
The reason the car feels pokey in 2nd around 10-15mph is because you are around 1500rpm, and the engine is making a lot less HP/Torque in that range.
You should get up to the rev limiter in all gears if you are really trying to be quick.
Hope this helps
