Would it be a horrible idea to keep it off? I'm the type of person where, if shit hits the fan, I reformat or just buy a new drive. I back all my stuff up anyways.
I think he's just suggesting a temporary disabling to clear up the fragmentation a bit, right?
I leave System Restore on. I've used it countless times on XP and Vista 64-bit when games or utilities have screwed up my system in explicable ways. The most recent time was when I futilely used a recommended registry cleaner utility thinking it would fix some Steam problems (Those were the ones I had to enable beta Steam updates to fix.). The registry "cleaner" caused my system to crash and produce blue screen error messages that I have never ever seen it do before and which it hasn't done since a successful restore.
A few games over the years have also fubared my system, and system restore to a day or two earlier has always fixed it just fine. Now the third-party programs I tried using earlier on Win98 and stuff that tried to do what System Restore does never worked for me -- they just made things worse. System Restore and I however are good friends.
If the price is a little more fragmentation, then screw it, I won't worry about it.