I agree with most of the posts here... but something to consider is the mobile ninja...
Some folks travel quite a bit and it can be quite the hassle to drag along an ext. hdd or even an entire folder case of DVD's to recover with.
This is the reason I took the time to create the thread detailing the replacement of the system restore image with a custom image.
I personally do not keep anything on cd/dvd anymore, all applications are in .iso format on a ext. WD 250gb HDD and mountable with PowerISO... I am not willing to drag an external hdd with me everywhere I go, and with all the software testing I do, I use CTRL+F11 alot.
Having that custom image within the restore partition has its advantages... If space is a concern, then you will probalby have an external hdd for storage anywyas and the 10-15 gigs will not be a large factor... but then again, if space is a consideration.. the purchase of the ext. hdd will allow for storage of the image files off the local hdd.
Either way is a good solution and I have no problem with anyones choice on this.
Just try to remember that not everyone is a noob just because they do not adhere to your methods of operation.
Just my opinion and $.02.