Draw time and relative difficulty; hand issues.
I suspect most of us are in the habit of practicing drawing from wherever we may carry. If there are any doubts about times required, or tendencies to snag on fabric or other obstructions, then more practice is indicated.
A couple decades ago, a kindly Gunny and his SGT assistant emphasized that on a really bad day, hands and arms might be disabled prior to the draw, so it was a really good idea to practice drawing with either hand, individually.
This is a MAJOR drawback to pocket carry. It's slow when using the primary hand. Try reaching across sometime... it's eye-opening. It can be done, but it is not easy.
This is probably the point where somebody will say, "but I'm aware all the time, I won't be surprised, and my hand is on the gun in my pocket." To which I'd say, you are more aware than I am, and you are luckier than I am - or you'd better hope you are.
The Gunny also taught how to cycle a slide with only one hand (using rear sights against a belt, boot heel, nearby wall corner, etc). For auto shooters, not a bad thing to practice every so often.