For that matter there is really no reason to have a G17 over the G34. They are essentially the same size except for a little barrel length. After mounting a light (I would suggest a Streamlight TLR-1) there would actually be no difference in length. This is because the light would stick out beyond the barrel of the G17 anyway. So length is not an issue, not for carry so weight is not an issue, might as well have the easier to shoot gun.
Other than price/availability. AFAIK, a G34 is about $100 more than a G17.