Apparently your mileage DOES vary. I must have extremely good luck with monitors because my two Dells are going on seven years old each and they're going strong. I've never had them open and personally have not been very comfortable with the idea. If something goes wrong though and its an easy fix there is no reason why I wouldn't go in them if I had to, now. The only reason I want to replace the SE198WFP is because it has some scratching that can make it hard to read (my fault, we were moving and I wasn't as careful with it as I ought to have been) and I want something with a higher resolution. Not for the better picture necessarily, moreso for the ability to read smaller text clearly and thus fit more on the screen before I can't read it.
I also have a couple even older 1024x768 panels (not Dell though, HP and AOC respectively) that, again, still work fantastically after at least ten years of service. The picture is a bit washed out (as LCD monitors were back then) though. None of these monitors cost more than $200 new, except perhaps the Ultrasharp, and I didn't get the Ultrasharp new. Well, maybe the old 1024x768 panels did. Machines were still sold with CRTs back then after all.