I think blitz Chess is a lot of fun. Lately I have been playing a lot of 3/0 on FICS. I have played over 1500 games over the last few months or so, and have over 2000 since I joined (November 2008). I believe I have gotten decent at Blitz. I generally play better Blitz than those who are about equal to me in standard OTB games. That said, my standard and correspondence games have suffered significantly as of late, and I believe the cause of this is the fact that I play so many 3/0 games.
Not too long ago, before I started playing Blitz a lot, my rating on RHP was generally in the low 1600s, and had been as high as 1684. Now I am barely 1400. I am struggling to stay there too. What has happened is that I now play all Chess as though it was 3/0. When I play anything longer than a 5/0 I get impatient. Now, I've never concentrated too much on RHP or standard games, but I used to put in some effort into calculation. I now play solely off of intuition. I have found that this is good in Blitz, but horrible in longer games.
I have, over the last week or so, forced myself to think more about every move when I'm playing here, and I have noticed that immediately my games have gotten better. This is of course common sense, but it is common sense that I ignored until being slapped in the face by being dropped 200 points.
So in conclusion I have learned a few things from this experience. 1. -- Playing too much Blitz can be dangerous. 2. -- I undervalued how much calculation makes your game better.
There is one positive thing, though, that I believe has come of all this. I believe my chess intuition has gotten slightly better. I think if I can harness this, and lose my impatience, my overall chess game will have improved because of my Blitz experience. That said, for me at least, this is not easy to do.
Just wanted to share my story.