There are no power differences what so ever. The main differences is in the suspension, and diffs.
The non-vspec uses a viscus clutch system for the front and rear diffs while the Vspec use a mechanical.
The Vspec has slightly stiffer suspension though some will argue that is not true. I know two people presonally with these cars and the vspec had slightly better overall suspension.
There is a slight difference though subtal in the front bumpers while the interior is the same. Some of the Vspecs came with white faced gauges while some didn't. That could have been an option.
Also I have seen two Vspecs one in both years with Gold emblems. Talking to one of the owners they suspect it was a gold key edition but I have yet to confirm this by any viable source. Other than that listed it is very hard to tell the difference even looking close between the two.