I've had the same Dell computer for 6.5yrs. I upgraded the vid card right away, and then this past year I went ahead and went from 512 RAM to 2Gig. I'm getting ready to switch from McAfee to Norton, but that's it, my BIL has a hook-up on that is my main reason.

I currently use an iPad for our IAP's/etc... and do like the functionality. I just don't know if I'd go for buying a Mac just because. If it was time to replace this computer, I would consider it with all the other options out there. I just use things until they crap out, or on the verge of it.