i don't like to go into all the reasons why SID is BAD as it's to long of a List =)
http://www.smdepot.net/forum/index.php?topic=2101.0for 1 many times in the middle of the install you code get a Error and if you Do then your going to have one big mess to try and fix as you'll need to Hotswap and copy over etc etc etc
2. the way SID installs is all wrong and as you Use your xbox it sooner or later Brakes down on you Most likely giveing you a error 21
3. I have had to Fix more Xbox's with SID installed then i would have Like to LOL
(Even when you want to Uninstall SID It's does not work out Like you want LOL as in Some times it will Uninstall EVERY thing and just wipe the hole drive)