Long time no post!....Limited edition problems

wow its been awhile, well the forum is nearly dead but anyway...I bought an owned but never used limited edition blue xbox off someone(he had it for he said almost a year but had only taken it out of the box to have a look at it, it was still in its plastic wrap and the front panel still had the removable plastic on it). moving on, now I've heard from a few different people about the limited edition xbox's being more prone to problems, as my friend had a new crystal xbox and I dont think it even lasted a year before the HD died. So far I think mine is very touchy with scratched or dirty disc's, I know I have a few used games that have some minor imperfections on them, but it was never really an issue with my old xbox, so far 1 of my games completely stopped playing on it, cause of the condition of the disc, and I've had a few problems with games freezing and me having to restart the xbox or in one instance I had bought a brand new game and it just didnt run very well, it was a tad slower, abit longer to load different things in the game, anyways if anyone knows anything further and has some advice I'd greatly apppreciate it, as I dont really want to have to buy another xbox.
Thanks