Thank you for the XD suggestion, I never really think about them when looking (the Glock blockiness I don't like ergonomically is just as bad on the XD), but they make high quality pistols, and they have one that looks like it will fit what I'm looking for perfectly. I don't see the single stack XDS you mention on the website, but I'd prefer more rounds anyway. For spring through fall use when wearing less concealment clothing, I'd prefer a smaller 9mm or .40 anyway. This gun will be a winter gun, so I don't have to go as small as possible (which is also why I'm wishing that there was a Glock between the compact G30 and the full sized G21). Anyway, the XD 45 Compact looks like it fits on paper perfectly (even better than the G30): 10 round mags (13 rounders available with an extension), 1.26" wide, 7.3" OAL (concealable, but with a decent sight radius), 4" barrel, 5" in height (very concealable), and 29oz. The XDM looks interesting and is a little smaller (27oz, 7" OAL, 4.55" height), but the 3.8" barrel, while meeting my minimum criteria, is pushing the limits of consistent .45ACP expansion.
Another gun that looks like it would be a good option is the S&W M&P 45. The M&P45 compact has an 8 round mag, a 4" barrel, and it is sized right: about 29oz with the empty mag, 1.2" wide, 4.8" height, and 7.55" OAL. The 4" barrel on the compact is nice so it can get reliable expansion out of .45ACP JHPs. They also have an interesting option, similar to a Commander sized 1911; they have one with the full size frame and compact's 4" barrel (instead of the full-size's 4.5" barrel). It differs from the compact primarily in height (5.5"), weight (just over 30oz with the empty mag), and capacity (10 rounds). Both the compact and the one with the same concept as the Commander would be high on my list, though I have never warmed to the springy M&P trigger so I'd have to get around that.