Spur gear size question

[VintageMA]

Can anyone tell me if the size of the spur gear really matters?

Aside from varied gearing options, is their any really noticeable effect of using a 44T versus a 48T in a 1/8 buggy?

I was reading the specs of the new Hyper 9 and it says:
The buggy accelerates and has greater top end speed because of the 11/43 gear combination at the front/rear gear boxes and the 13/40 combination at the center differential. The faster spinning center differential also reduces the torque effect of the engine.

http://www.nitrohouse.com/details_hyper_9.htm

I know the new xray 808 went in this same gearing direction too.