What's more important for conceal and carry?

I pretty much know what brand of pistol I want to buy for conceal and carry, just not sure on what model. Should I go for comfort and get a sub-compact (Glock 27 as an example), or get a larger framed compact (Glock 23). Again, I'm just using Glock as an example, so please, no heated debates on favorite gun brands. I feel much more comfortable having the larger framed pistol, but I'm wondering if I'm more likely to carry a sub-compact a lot more often if it's more comfortable. Also, I'm guessing that the likely scenarios of a gun toting civilian probably won't demand the advantages the larger framed guns provide. Anyone out there have experience with this?