Only downside are the really crap screens unless you go IPS. My el-cheapo Toshiba laptop that I got has a screen that kills my Thinkpad screens.
Same deal with Lattitudes, though I dislike their screens more-so (it's the harsh blue backlight), and their trackpads and titmice cannot be configured to have as low acceleration as a Thinkpad's (I have a brand new one next to me right now, and that built-in acceleration is annoying enough I wouldn't be able to use it day to day). Build quality is roughly equivalent between them, IMO, but I think Lenovo at least gets opinions of humans, about the display and input

. HP's build quality goes from so-so to good across their business line. The ProBook 400s, FI, are so-so, while the Bs are rather nice.
My R60 is starting to lock up once in awhile, now...after buying it, "as is," straightening parts out (the aluminum hinges are made to take some impact, and they do...but they don't stay straight in the process), replacing the DC jack (that and the battery were all that were busted),
and then it taking several roughly 3 foot drops to hard surfaces, while open, including putting 2 dents into my floor, both of those from landing
display-first, yet no damage to the display has been evident.
Like everything else, the new ones aren't quite built like the old ones, but they're still built better than most, and neither HP nor Dell seem to be able to
consistently implement a good keyboard, trackpad, and trackpoint, all in the same unit, while Lenovo manages to. It's not just that they're designed and built well, but that they stay that way, generation over generation. Dell or HP may have a few series with good keyboards, then they go to pot. Same with trackpad and display. HP usually has a decent display (not for people picky about displays, but not bad), but seems to randomly choose a keyboard and trackpad per series, from what I've been able to tell.