I didn't like it as much as the 9mm. The 9 felt much more usable and comfortable. If I could get a super-extended mag, I'd be happy to use it as a range gun. It's a good size and would be a great everyday shooter.
When I was shooting the 40 I kept having the mag fall into my supporting hand when firing. I wondered if I was hitting the mag release or something, but after several very intentional shots, confirmed I wasn't. I had my son shoot it and he experienced the same.
It wasn't later that I discovered this was a somewhat common (but by no means universal) occurrence. It was then that I found out S&W was correcting the issue. So, that wouldn't be a deal breaker for me.
I just didn't dig the round with that gun. I'd been wanting to like a 40. I'd gone through a variety of guns trying to find a 40 I could like enough to buy one. But this one wasn't it. It wasn't until later that I realized the rounds I didn't enjoy shooting as much were all high pressure rounds (40, 357 Sig, 10mm). Don't get me wrong -- I enjoy shooting them, but I find I can't get a sight picture as quickly with them and overall just don't enjoy them as much as other calibers.
Once I realized the commonality of these rounds (being high pressure) I just sort of stopped my hunt. FYI, that was just a few weeks ago...