I think the operative question is: with which can you put the mostest holes the closest together in the shortest possible time?
I have a .40 bbl for my Glock 32, but don't use it much (mostly 'cause I don't care much for the .40, rather than fear of kB's). I was thinking abt this unsupported case issue last nite, and again pulled the 357 SIG and .40 bbls from my G 32 and SIG 229 and 226 to look them over. The relative lack of case support in the Glock is really quite striking. In 357 SIG, it's still less supported than in the SIGs, but prob only 1/3 or 1/2 as bad as in the .40. While a lot of Glock kB's seem to be ammo related, the lack of case support is very real, and overall it seems that the Glock .40's are less able to handle whatever combo of factors it is that causes the kB's than at least some other brands. My personal opinion is that Glock is a dish best served in 9 mm flavor per its original design, which is why the G19 is my most frequent carry gun. I have much less reservation re using the .40 with the SIGs, as the 229 was designed for the .40 and the 226 slide was changed accordingly from it's 9 mm form. That is, other than knowing that hotter rounds like the .40 and 357 SIG will likely accelerate wear (as would 9mm +p+ or a lot of +p's, for example).