Well, I have not ridden the ST or the Vaquero, but I will give from what I read and heard. Both the C14 and Vaquero should satisfy your acceleration needs - the Vaquero has good torque down low while the C14 got gobs of both north of 4k rpm. The C14 acceleration can get downright scary if you grab a throttle full. There are lots of pros for both bikes, so let me state some things to consider.
C14: If you have not sat on this bike or test ridden it, you should. The bike puts you in a bit aggressive sport position, making you lean forward. You will need some aftermarket support to remedy that - not expensive, but gotta spend the extra dough. This position is really good for a person like me that cannot sit on their tail bone for more than 10 min. I have ridden the C14 for 400 - 500 miles at a stress not breaking sweat. Not something I could do on a cruiser style tourer. Another thing to consider is how tall this bike is. If your inseam is at least 32, you should not have any issue. Some folks had to lower the bike by an inch to feel more comfortable. The bike is top heavy - so you will need to get used to it. But to me, that is a pro because taking corners is a breeze. The top heaviness rears its ugly head at very slow speed. But once you get used to it, its like any other bike.
Vaquero: I have never ridden one, so I am going by what I read. This bike will have vibrations - lots of it. It is designed to do that - capture the V-twin spirit I guess. If you do not want the vibration, you might have to settle for the 1700 Voyager or Nomad, not sure which has a counterbalance. This bike sits about 4" lower than the C14, which makes it easier to throw your leg over. But you cannot corner it like you can the C14. Since I have not rode one for a long distance, I cannot comment on the overall comfort. I am sure you will have to tweak seat, handlebars, etc. to get to your comfort level.
I was a cruiser style rider until two years ago - and now I will not give up the C14 for anything - maybe another similar bike. And my reason for that are the riding position, which puts your weight more on your legs and wrist/shoulders, rather than your lower back. And the power on tap - you can cruise around all day pretty bland and boring, or you just twist the throttle and leave all the Vaqueros and Nomads in the dust.
Best recommendation is to go at least sit on each and take a test ride. If you are used to a cruiser style bike, the Vaquero might feel a bit more comfortable. So keep that in mind when you try out the C14.
