Rarely. I only send it back if it's due to bad handling or just a bad bottle. Despite all the hullabaloo about screw tops vs. corks, I've been fortunate enough to have pretty good bottles at the restaurants I've been to.

The last time I sent something back was because the serving temperature was too warm and they had obviously had improper cold storage (easy to find on a hot day -- never had wine there again).

More often, I wind up sending my espresso shots at restaurants back. They screw those up (overextraction) far more than they seem to botch a bottle of wine -- or wind up with a lemon.

Wow, never even thought about sending espresso shots back...but now that you say that I gotta' confess to getting more bad espresso than wine.

That said, the amount of corked and off wines out there is huge.

Yes I've done it, but only for a bottle that's gone bad. I've been out to dinner with people who have sent back a bottle just because they didn't like the wine, which I don't think is cool at all.

wow, I haven't sent back a bottle of wine in over ten years now. The last time I did, it had gone bad. Some places here in New Orleans don't have good a/c in their kitchens/storage areas, and the heat will do their wine stock in if they're not careful.