The sizes you were referring to are:
VCD VideoCD (1152kbps, mp2, 352x280)
SVCD SuperVCD (2.5mbps, mp2, 480x480)
CVD CVD (2.5mbps, mp2, 352x280)
DVD DVD ( 3mbps-8mbps, ac3/dts/mp2/pcm, 720x576PAL/720x486NTSC)

In some ways vcd format reminds me of web format, although there is a diff. But on TVs we don't quite notice the diff quite so much due to the way Standard TVs load the data. (Web quality looks crook however~!!!)

Of course HD video hasn't reached the dvd market as of yet as far as I know (let's ignore the cheaper/lesser res 16:9 versions at the moment.) Perhaps if/after the 'Blue light' spectrum dvd (compared to the red) format comes out it might be a better thing for the various HD formats. Commercial dvd's started out at about 4mbps. Are we getting cheated here?! The technology is here for HQ dvd & formats of HD viewing, but we 'MUST' wait for the marketers to finish their staged out practice of 'just a bite at a time' process. eg: After all Mac had a 1 GHZ sitting around when their G4 4-500Hz had just reached the market (it was 1998 when I read an interview with an Apple exec.). It took a few yrs before we saw it! HD cameras for the domestic market have only recently reached the marketplace. Personally I'd wait a while until we see the improved versions instead of the initial rough, low-level, no-luxury versions. After all, that's what marketing is all about. I'm getting off the topic now.
Depending upon the softw you're using, some will be able to do a reasonable job w/o losing 'too much' visible quality. But some will not do such a good job! Ansd some do squish them onto one CD. Some softs do relinquish the menus to help reduce size. dvd burners & players are almost dirt cheap now so why not go out & get them instead of compromising upon your visual (& audible) enjoyment ... either for comp. or TV.