The reason I went with the 290 was because I don't want to JUST mine, I want to game as well so that aspect made the 290 more appealing to me.  I had the GTX 770 and by simply switching to the 290 I'm going to get about 3x the performance when I am mining and slightly improved gaming performance.

If I set up another rig solely to mine, I'll go with a different card of course.

Personally I see bitcoin continuing to do well and Alt coins continuing to go up.  With the current ROI of about a month, and the potential to mine other coins, it seems like a risk work taking to me!