I had three Dell "work" laptops prior to the current MBP, a CPx, a D505 and a D520. The CPx was from 2000-2003, the D505 was from 2003-2006 and the D520 was from 2006-2008 ... yes, I got out of the last Dell a bit earlier than the normal 3 year HW refresh cycle. The CPx had the keyboard replaced twice and one of those times, they replaced the MB, but just as a precaution. The D505 had a wireless antenna issue for which, they replaced the MB, Wireless card, and finally the antenna. The sequence for that one was that they sent me the wireless mini-pci card and I did the swap myself. When that failed to fix it, they sent a tech to my house with the MB and antenna the next day. The D520 did not require service. One of these laptops did get a new battery in a battery recall, but I can't remember which one. In all cases, if the tech was doing the repair, they were either at my office or my house the next day. In the case of the wireless card, it arrived the day after I called Dell with the issue and the tech with the MB/Antenna was there the day after that. With the CPx, I was not docking the laptop and used the laptop keyboard as my primary keyboard device. With later Dell laptops, the laptop was docked and an external keyboard used when at home or in my office. With the Mac, I am always using a USB keyboard when at home or in the office.
So, if you are alluding to the measure of HW quality versus amount of service pain I am feeling, I am not sure that it is possible to quantitatively measure the value of on-site, fast, deterministic, but more frequent repair versus non-deterministic, must take the equipment to repair shop, possibly less frequent repair.
Others on this thread have implied that any enterprise use of a Mac laptop is not in keeping with Apple's focus on consumer products. I would argue that Apple has been courting enterprise users with the changes to incorporate Exchange connectivity in to various productivity applications. Apple needs only to step up to the plate in the area of support to truly make an enterprise user have the equivalent service that others already provide.
While I am sorry for your delayed service, Dell (with our corporate contract) has always shown up within 24 hours to make a repair.