There is a huge modding community, but you don't really need to go that route if all you want is a reliable laptop. Although you might need to change the battery and fan, they're after all 8-10 year old by now.
I do have a recent Dell Inspiron, but I find I'm mostly using it like a desktop, with an external keyboard and trackball, and a second monitor or TV set plugged in. I just can't stand trackpads.
At least for me, this is half the appeal of thinkpads. They cost so little for their performance, I have a mate that even got a couple for free.
Most of mine I didn't even need to change anything. The fans still work nicely (sometimes given them a clean of course) and no real battery problems to speak of. Probably a good idea to anyway, but yeh, they're solid laptops even after all these years