I like Deadwing as well. I didn't grab me a quickly as In Absentia did - that was the first PT album I heard and I loved it immediately. I think Deadwing is like a lot of my favorite albums though, in that it takes many listens to fully appreciate. I'm seeing them live in two weeks so that should clinch it.
Oh yeah, having Adrian Belew play on two cuts can't hurt...
Signify is an interesting counterpoint to In Absentia and Deadwing: more experimental and moody, less hard rock. Deadwing is in some ways more like Signify in this respect. These guys really have a broad range of styles and compositional approaches across their three latest albums.