Dust can be cleaned off. Normal physical wear will inevitably happen on a dvd drive. Since 360 drives have a unique matching serial number, they cannot be replaced (unless you have cloning equipment). A dead hard drive, on the other hand, is easily replaceable. 

Many  different types of hardware failures are possible: calibration issues, motor issues, etc. In the past, some x360 drives were scratching discs, etc.

Drives can and will eventually fail; 4GB models, because they don't have a hard drive, are statistically more prone to drive failure because they use it more often than 360's with the games installed on them.

this is just completely unfounded outside of your own opinion, the same could be said that the 4gb model is never going to suffer the stress of reading an entire disc at once which is only done ever during the installing process as such they would avoid such stress and not buckle under it.

You can't play all of them online with the 4GB version some require you have a HD.
But someone beat me to that... nothing really for me to add....

Reading an entire disc at once: Sequential access (linear, constant/regular motor speed, etc.)

Gameplay is closer to random access, which means higher stress on the motor (lots of variation in speed, stop/start, etc.)

Ask yourself this question: Between driving a car at a constant 50mph on the highway or going through heavy traffic, which is more stressful for your engine/transmission? This is the same as a drive spinning up and down at high intervals. 

Nevertheless, It is my (fact-based) opinion and my money. Consequently, I bought the 250gb version. 

160gig is $250

320gig is $300

The Super Slims are..
250gig at $270
500gig at $300

So only a price increase on the low-end model. But I got a feeling there's is a lot of room for a price cut(especially on the 250gig). Most likely around Wii U launch.

@VGKing You think Sony is going to release the 250gig now at $270 only to cut the price later when WiiU launches? Are you really that desperate for a price cut from them?

not gonna continue to quote that huge block mr poro :D but the xbox hardware to be honest is as likely to be affected by a passing breeze as different rates of reading discs, I still have my original elite model pre HDMI port on it, my bro got one same day as me and it died just as the slim came out so he got a slim 250g I think it was at the time, which had it's drive fail and need to be returned for refurbishing. Xbox360 hardware is just a case of hope and care really :D Why I say that the amount of reading a 360 laser can do before it dies.... well I've still not had an issue and here are the handful of games that been through my system :D

http://imgur.com/WXiFQ
and yeah like I said the thing is at least 4 years old at this stage and only thing I did to it was replace the hdd with a 120gb one since when I bought it the top of the line was 60gb I do install games if I know I'll be in it for ages like skyrim or fallout but for the most part just play from disc. I will give you the point on the car tho, I see entirely what you mean by unexpected speeds and jumps and I do agree that could be more stressful than just a full 100% read.

I heard that the Jasper elites were among the best 360 revisions, especially when it comes to heat production/dissipation. Glad to hear that you have a durable model -- and a very nice-looking collection. That "passing breeze" tidbit brought a huge smile on my face. The thing is, I'm so used to dealing with broken hardware that I take very very good care of my stuff :)

Paranoid! haha.

But remember that those are bundles, there's no official price on the stand alone new super slim I'm going to guess that after the holydays the 250GB stand alone super slim will cost 250$ and the 500GB stand alone super slim will stay at 300$.

I know man I'm the same with mine, I always do have a thought in my mind when you hear horror storys of consoles ripping up discs just get an image in my head of people jumping up and down with it in their hands as it tries to load, I still have pretty much every game and console that I've ever had as a gift or bought myself in my 29 years on this planet, my original pong machine still works with its lil speaker on the unit and wheely paddle things, still looks nice on a 42inch hd screen haha... just blinding because the cables for it's controllers are maybe 6 inchs long but still, I'm rediculously careful and respectful of any hardware I own. I think a lot of peoples issues with hardware could be user related at times.

....... ughhhhh just remembered that post is 99% true... sigh http://imgur.com/ICju9 as much as my master system 2 is rushing to help it's fallen brother... that's what remains of my original psp1000 literally played to death, the ribbon that runs under the screen and has start/select and the brightness buttons just ripped from being pressed too many times, woke up one morning and just found the thing completely messed up, got a replacement ribbon from ebay for it but the chinese knock off I got ended up breaking where it goes onto the pcb too, a very sad day and I think it was replaced in about 5 mins giving it takes 4 mins to find my shoes and the game shop here is about 20 mins away from my house love my psp.... lost my disgaea save tho.... damn thing was locked to the dead psp so had to restart that.

But yeah! I'm a fellow fan of minding hardware above and beyond the call of duty! love gamin too much lol.