I vote for keeping the 19 as well because it is the most versatile in terms of carry, plinking, etc. seems to do everything well. Although, if you ever foresee replacing the Glock you sell, keep the 34. These seem harder to come by and a tad more expensive than the typical 19.
I agree with that thinking. It would hinge on if you carry the 19 or not. If you carry the 19 then keep the 19, if you dont then I would certainly keep the 34.
What gen is the 34, its on my "want to buy" list?