Like they said, either one is a great choice. Its really hard to say, I have two glocks and one is a 23(same size as 19 diff cal) and I love that friggin gun. With that said, I want a sig, xdm and a m&pc in 9mm. Just hold both guns and which ever one feels the best go for it. If you can shoot both that would help also.
I'm not a big Glock fan, I like em and they do everything well but they just don't do it for me. We have a M&P 9c and a G19 gen3, I'm a better shot w the Glock but I carry the M&P most of the time. If the 9c had a slightly longer barrel I'm sure it would be just as accurate as the Glock. My only regret is not getting the fullsize since I open carry 99% of the time.