Because they made a album with better recording quality, that makes them sell-outs? Not really. I'm pretty sure they weren't thinking about selling out on Lateralus when they wrote the 8+ minute "The Grudge", or the companion tracks "Parabol" and "Parabola." Each Tool album has a different theme, and the mood of the music adjusts accordingly. Don't fault them just because they had more freedom on the third record, as well as an opportunity to make an album with a bigger budget. They're a PROG-ROCK band, which in these days, is about the farthest you can get from selling out. When they're writing 4 minute verse-chorus-verse songs about ex-girlfrienRAB, then you can tell me that they've sold out.
That being said, 10,000 Days is a great album. It takes a few listens, but it's fantastic. Has the same production quality as Lateralus (so you might think they've sold out again ), and features multiple 9+ minute songs. Somewhat of a stripped-down sound when compared to its predecessors, which gives way to a raw feel on some of the tracks (see "Jambi" and "The Pot"). Overall, I would argue that it is the most cohesive Tool effort to date. A great album by any standard.