"dark side"... opinions.
anyway yes if you talk about games from hd there is nothing better than it, it's continually being developed if you see the latest days news it seems to be able to boot even gt4 from dvd or hd with the beta (not released) version.
anyway you can see other better compatibility a stupid example very little:
mgs3 : snake eater USA
if you use hdl first you need to patch it or it don't work, then you can't use the soft reset => BSOD. with toxic os simply copy it to hd and play from there and it works like from dvd (only more fast).
other things are faster bootup.
hope to see the same capabilities on other chip/no mod console, maybe who knows look at the homebrew hd demolisher project, there is nothing else and at the moment it don't play games from hd (actually if i load the cvs version i get a good exception handler, btw)
ps2os betatester, ps2tools codev, hdldump frontend dev
6 sony mc w/ps2os 0.2.4, hdl, ps2rmp1.50,ps2mp3...
na+hd maxtor diamondmax 7200 120GB
PS2 SCPH-30004R V6 ÐM$3 V2 firm 2.4 B.4
PS2 SCPH-50003 V9 ÐM$4 PRO firm toxic os 0.1