Some of my personal experience with these 2 strings. I played 2 matches with both strings. In each match, I played 1 set with each string. Both strings are at around 4-6 hours usage.
1. SPIN: I can generate more spin with velocity 17. I have more confidence with my approach shots when using Velocity, where the ball flies with a good launch angle and can dip into the court. I missed more approach shot & passing shots into the net with Multifeel (may need to further work on my technique). I feel that velocity can pocket ball better, that's why it can generate more spin.
2. POWER: Multifeel 17g has more power than Velocity 17g. That's probably why it has less spin. However, the power level of velocity 17g is not very low either (it's probably medium).
3. FEEL: Multifeel has a crisp feel. You tell it from the sound of each hit. Velocity 17g has a soft/muted feel (it's not as crisp as Multifeel)
4. COMFORT: both strings are pretty comfort to play with. However with a history of Golf Elbow problem, I need to make sure my hitting arm is relaxed and I'm not late with my shots, as I know even for a multifilament, I can accidently hurt my elbow.
5. SERVE: I have faster flat serve with Multifeel. I have better spin/kick serve when using Velocity 17.
6. CONTROL: due to velocity can generate more spin, it has better control than Multifeel
7. STRING MOVEMENT: it doesn't bother me, but I think Multifeel move more than Velocity
8. PLAYABILITY DURATION: TBD
9. DURABILITY: TBD (but I think Velocity is more durable)
So I've played more with Velocity/Multifeel 1.30mm/16 gauge in my matched VCP HDs. Here are my findings:
Spin: On paper, Velocity should have more spin with its slicker coating. In practice I'm much more comfortable taking big slices at the ball with Multifeel which shapes the ball better. Velocity feels like trying to grab something with oily hands. It's slippery, overly so and in a bad way. The first few hits were awful with Velocity and the string seemed to throw unexpected spin everywhere. It felt better after a while once the coating started to wear off. Some people have games that work better with this sort of string response. I don't feel that way. YMMV. From a purely objective sense, Velocity has more spin potential, I just can't make use of it. So a phyrric victory for Velocity, I guess.
Power: About the same.
Feel: Multifeel is all about the FEEL as the name suggests. Multifeel has a nice crisp feeling on contact. Love the sound it makes too. Velocity has a very muted spongey kind of feel, like you added a vibration dampener to the stringbed. It doesn't work with the VCP HD's VDM (handle vibration dampening system). Since the VCP HD already has VDM in the handle, so you lose all feeling of the ball on the strings. Because of this effect, I couldn't dial in my strokes at all and suffered horrendously. It's similar to adding another dampener to the frame.
Comfort: Both have a similar amount of comfort. Both are super comfy.
Serve: Multifeel feels more like a consistent stringbed to me, so I serve much more consistently with it. Flat or slice feels more predictable with Multifeel.
String movement: Velocity moves and then stays bent out of shape. I don't need to adjust with Multifeel.
Durability: Velocity seems to last longer and hasn't frayed as much as my Multifeel would be at the 1 month mark.
I prefer Multifeel over Velocity. When I hit with Velocity it feels like I'm playing on a bad day. Once I switch back to Multifeel I feel confident again. It feels GOOD (crisp, good feel) to hit the ball. Velocity feels like mush (VDM damp + string damp = damp noodle feel) and is super unpredictable to me. I hate Velocity in the VCP HD and I'm cutting it out on Thursday and trying black Multifeel. I feel that strings, much like racquets are deeply personal, so people many appreciate Velocity more. It's just not my type of string/doesn't do what I want it to.