Personally i prefer a longer ratio box and i think once rolling they are actually quicker up to a point, ie the series 2s 3.82 vs the series 1 4.?? In a series 1 or xr3i you are always changing gear and its revving its tits off at 70/80mph whereas the Series 2 is relaxed at cruise and you dont need to keep changing.
Eg - an Xr3i or series 1 won't do a genuine 60mph in 2nd (standard rev limit applied)
whereas a series2 turbo or orion 1.6i will, as they have taller final drives.

In gear the shorter box maybe quicker but from say 50-100 there will be an extra gearchange so it ruins the advantage?

Karlos - was the 3.58 from a diesel?

Im tempted to try a longer final drive (maybe the 3.58) for an even more relaxed cruise (circa 2500rpm @ 70mph) and so i can use 2nd on roundabouts etc, as i currently use 3rd and its just at the point of spool up so 1/2 way round i hit boost and it upsets the car.

IMO with 300bhp i'd go for the taller gears as the torque and power will pull thru nicely, and the shorter ratios will just be wheelspinning and hitting limiter etc.