So I've seen exactly one pro (a high-dan Korean) that clearly recommended blitz rather than just tolerating it. It was one of those cases where a pro shows up at a U.S. Go Congress for the 1st time, sees the time settings in the U.S. Open, assumes those are typical, and wonders what we thinking in the West. (To be fair, the U.S. Open time settings are slower than many Korean pro tournament settings.)
Anyway, he said that, say, a 5 kyu should play 10 minutes absolute. Shoot for 10 games in 3 hours. (It should be possible considering that in absolute time most of those games won't take up the whole 20 minutes.) He did not say he recommended it for stronger players (though he did not say he did not.)
I actually tried those settings and found them easier than intermediate settings like Canadian 1 minute + 25 stones in 5 minutes that I used to use on IGS a lot. Around that time I decided to drop intermediate settings. Then later I found this interesting comment from one of
Dan Heisman's articles on chesscafe.com:
Play as many long time control games as possible (30+5 or, preferably,
slower). Until you are 1700+ FIDE/USCF, avoid intermediate time controls
(ten to thirty minutes per game), which may entrench poor/hasty thought
process habits. Taking your time in slow time control games is an important
step in learning how to analyze moves carefully, comparing various candidate
moves to see which offers the best chance. Playing slowly and consistently
and analyzing and comparing is a necessary part of improving that skill. You
are a better chess player when you learn to chose better moves, so taking your
time and learning to consider move options better is about as important a
skill as you can practice.
3. Once you are past the beginner level, play plenty of speed games mixed in
with the slow games. But make sure to look up your openings in opening
books (databases are not yet as helpful, although they do offer some benefits),
so you don't keep making the same mistakes. At a recent talk at our club,
former U.S. Woman's Champion Jen Shahade also emphasized the
importance of looking up openings after speed games; I just sat and smiled.
Importantly, play speed games with the same increment or time delay as your
important over-the-board tournament games. Failing to do so will train your
brain to think sub-optimally when you run low on time in those important
games. If your important OTB games are played at a thirty second increment,
then perhaps a five second increment for speed games will have to do.
So I thought, hmm. Similar idea. It's not the fastest blitz that's the problem. It's the stuff that's in between your tournament-length games and the fastest blitz that gets people confused. Unfortunately, his comment on consistent increment seems weak, as he immediately pulls back on it.
In favor of blitz, it's definitely one way of testing new openings.