So, you are wondering what to buy to get you moving on through the summer doldrums on a twin tip. Of course, if you are using a foilboard, you can go much smaller.
Let’s start with the Soul 21. It is big, slow, stable, with a great range. I fly it is 4 to 20 knots on the snow and 8 to 20 knots on the water. It is an awesome kite. So what do you get with the v2? I think it boosts a bit better, has a bit less bar pressure and the new fabric should last longer. So, it is kind of like buying a new car vs a used one. If you can find a Soul with little mileage and a low price, you might be just as happy with the Soul, but compared to a well-used Soul, the v2 is going to be better in almost every way.
Sonic3 21 - Flysurfer recommends this kite for heavier riders (110 kg). After flying this kite several times I understand why. Lighter weight riders can handle this kite just fine, the issue with the Sonic3 21 is that it does not handle light flukey winds as well as the Soul. So, if you have stable winds where you ride, the Sonic3 will excel because it does boost better and has better hang-time than the Soul, but it is less stable, you are more likely to have tip folds and/or bow ties in wind under 10 knots.
VMG2 23m - if the Soul is a Porsche and the Sonic3 is a Maserati the VMG2 is a Ferrari. It does everything just a bit better. It is quite stable in low wind due to the fiberglass battens. It boosts great and the hang-time is unreal. However, it has some issues that make it troublesome. The bridles are super thin and the bridle design is not designed for relaunch, it will relaunch in decent wind, but this is a kite you don’t want to be dropping in the water. The fabric is also extremely light weight, so you have to be careful with it. Add to that the high price and you have a kite that while super fun is not practical outside of racing. However, like Ferris Bueller would say, “It is choice. If you have the means I highly recommend picking one up.”
Back to the real world, if you have less than $1k to spend and you weigh over 180 LBS, by all means pick up a gently used Soul 21. 150 to 180 LBS, Soul 18 will do. If you can afford new, the Soul v2 is superior to a Soul. The Sonic is a good choice for heavier riders or riders that ride where the wind is smooth and laminar. The VMG2 was never designed for twin tipping, but it is a blast on a twin tip and for snow kiting, it is the most amazing kite I have ever seen for gliding in light wind, but again, it is not a practical kite.