Software or decoder card, that is the question. (DVD)

[Ironforge]

Well, I have the following setup:
Toshiba 6x DVD
P3-450
using winDVD 2000

runs great.. hardly lags at all..
of course a decoder card will look/run better.. but for me, not enough to go out and spend 50 bucks on a reelmagic hollywood+ card..

[Pack'nHeat]

Hello.
I know if you have a CPU above xxxMHz you don't need a MPEG2 card to use with your DVD. DVD software is fine. BUT if you have a 700MHz CPU and you use a MPEG2 decoder with your DVD any way, will it look or play better then with software support only? Thanks, ~