If you're going to CC with a light on it, then, depending on the light, the only concealment disadvantage to the 17 would be the overall frame height. If you choose something like the popular SF x300, your overall length is going to be at the 17 length anyway.
I have concealed carried a G17 a good bit, but my height makes it more doable for me than for most. Even still, I much prefer the G19 for conceal carry.
I also believe that a lot of the factors, such as front end weight, sight radius, the different target acquisition with a red dot vs irons, etc. are resolved most effectively with a lot of practice. Once you're really familiar with the specific weapon setup, muscle memory starts to take over. Not a new thought, of course, but it may be a mitigating factor in the decision making.