.45 or 9mm. The age old debate. I have yet to hear of a "bad guy" that continued to attack because he noticed that the victim's weapon was "just a 9". Getting shot is getting shot regardless of the caliber of the slug. Most "bad guys" turn into Carl Lewis when the report is directed their way. For the ones that have modified their cranial chemistry you can assist them by creating a drain port in their skull for the poison to flow out. Just one man's opinion.
I can't speak exactly to the 26 vs the 30 but close. I had a 30 and it was one of the most accurate pieces I've ever had. It would cut a large jagged hole in paper at 7 yards. My current 27 (.40 cal) isn't as accurate as the 30. However the 30 was a little bulky to carry. I currently carry a 23 (.40 cal) on my ankle and it hides beautifully. It has all the power I need and is plenty accurate.
I dress for it. I've worn high work boots for a couple years and the ankle holster rides down on top of it and I don't even feel it. I have boot cut jeans that are nice and loose and hiding it is no problem. It might even be a tactical advantage in case a thug is trying to make potential threats before he pulls some s***.