I recommend the Atom because Paradigm just drastically restructured their lineup... the Performance series (previous low-end) has been combined with the Monitor series, with the low end falling now to the Cinema series of home theater speakers. Also, the Atom Monitor is more expensive than the old Atom (well worth it; the Monitor series tweeter blows the Performance tweeter out of the water) and tops out the requested price range.
For more serious listening than just home theater, the Atom Monitor is the most budget conscious thing they offer now; the Titan model from the Performance series you are thinking of, RedLeader, no longer exists (just check
www.paradigm.com). This is a very recent thing, but IMHO they made the right call. After they expanded the Cinema series, Paradigm had two many speakers available at overlapping price points and this move simplified their lineup considerably, also making their new low-end technology the Monitor tech rather than the Performance tech, which is a very good thing.
Even if the new Titan Monitors were in the price range (they are not even close, with a MSRP of $499), I don't think I would recommend them over the Mini Monitors which are $379. Paradigm has perfected their 6.5" woofer, and to my ear the 8" version doesn't sound quite as good. When I was initially shopping, I thought the Mini Monitor and the Monitor 5 both sounded better than the Monitor 3 (Monitor 5 is what I went with, Mini still exists, Monitor 3 is now the Titan Monitor. Confused? So am I...).
TreAdidas - those sound really interesting, I will have to look for an Acoustic Energy dealer around here and audition a pair of Evos or Neos. Which Monitor did you have? I love my Monitor 5's (version 3, if it matters) and can listen to them for hours on end with no fatigue, but could perhaps use a set of smooth smaller bookshelves for my computer. I'd love to hear a pair of Neos side-by-side with my Monitor 5's, or just get your impression in more detail.