CCW 7 Rounds of .45ACP or 11 Rounds of 9MM?
Perennial subject topic ...
My answer?
Sure, one or the other ... or something else if appropriate.
I started my LE career carrying an issued 6-shot .357 Magnum revolver and mostly either a Colt Commander or .357 Magnum off-duty. I later decided a 5-shot S&W M36 wasn't a bad choice at times for off-duty.
At the end of my career I found myself carrying an issued compact .45 (7+1 capacity) on-duty and mostly a J-frame .38 Spl off-duty.
Between those times I carried a LOT of different makes/models, both issued and personally-owned, chambered in various calibers. My issued pistols ran to models chambered in 9, .40 & .45 and included mag capacities of 14, 15, 12, 9, 8 & then 7 rounds.
My current choices in retirement pistols include 9mm, .40 S&W and .45 ACP, and the magazine capacities include 6, 7, 8, 9, 10 & 12 rounds for the various makes/models. I also have a handful of J-frames I like to use.
While I leaned rather strongly toward .357 Magnum and .45 ACP as a young cop, nowadays I tend to lean more toward .38 Spl (+P) and 9mm choices, with .40's & .45's following a bit behind.
Why?
Overall smaller size of the guns is one reason for me choosing the 9's over the .45's. Also, better controllability & recoil management is another reason I tend to favor the 9's over the .40's & .45's.
I like the J-frames because I'm a long time revolver shooter and like their handy size (but they're often hard for most folks to accurately and effectively shoot).
Capacity? Well, some folks have strong opinions about capacity. I don't make it my business to try and tell anyone else what they should think in that regard.
Instead, I usually ask them how well they can safely manipulate, handle, load/unload, and shoot whatever their choice may be in the way of an off-duty/CCW weapon. I let them see for themselves how well they can perform with their choice under various range drills, especially the more demanding ones which require more than just standing still on some firing line and shooting at a stationary threat target.
I tend to look at things from the perspective of knowledge (laws, tactics & strategy), awareness (environment), mindset, skillset and then tool-set ... with "capacity" being under the "tool-set" category.