if for the performanc wise, rack stuff would definitely give more to the end user, imho.
heh, tweaking wise, theres definitely more things to play with then average pedals and stuff. But can be hassle to bring rackcase around(for gigging purposes) and if anything goes wrong half way thru shows, it can be a nightmare.
if just for home playing, recording and stuff, rackmount can be a useful tool, combined with music softwares. Might ended up tweaking too much and not getting the music out.