Keep in mind that I've only directly compared my Theater 4s with a pair of regular cabinet 2's and these were with the old motorola tweeters. That said, the two speakers are very different sounding but both sound very good. The 2's are bright, brash, and quite capable of impressive macrodynamic air movement. They do boogy very well and sound way bigger than their size. The Theater 4's are considerably more refined sounding and balanced. They are capable of impressive macrodynamic swings but really shine in developing a most impressive soundstage with microdynamic information well layed out in 3D. In my listening room I can't really get the 4's really cooking on rock due to the lack of size(11x17) but with my 2A3 amps' 3 Watts and classic jazz recordings I'm always in seventh heaven with the 4's. The 2's actually did better with rock in my room (same amps). Standing waves are really a problem which I can't do much about (WAF).I think the 4's are best if you have the room and budget.
G.