I own 2 Sabvoton, a 72150A new generation and a 72200A (software unlocked to 200A), previous version
I've also got a Kelly KHB12401.
So far, I tested all those controllers on a 72V 35Ah lead acid battery, on my electric motorbike, with 16 inches 3000W QS V3 high speed motor.
I'll only talk about the 72200 vs the 12401, since the 72150 is pretty much the same as the 72200, only with less power.
My opinion:
Hardware set up: I really don't like how the connectors are done on the Kelly. They need screws and bolts, they protrude a lot outside of the controller box and they need very careful insulation. On the sabvoton, the connection of power wires if pretty much fool proof, you're less likely to make bad contacts between terminals.
About the low power wiring, they are pretty much the same, the indication markings on the Sabvoton are a bit clearer though (I had a hard time figuring out what was the ignition wire on the Kelly... it was a pink wire marked "PRW", I thought it was a red wire marked "B+" which would have been far more logical).
Size and heat: The kelly is quite bigger and heavier. So far, according to my tests, they are heating pretty much the same.
Software and configuration:
Connection to the controller is a bit easier on the Kelly, no need to select the right port, it is done automatically. The Kelly manual notice is stupid as shit, it mentions that you should absolutely remove all wiring from the controller and supply it with 10-30V to make any programming, while it is actually not necessary at all and works perfectly fine even when all the wires are connected to the machine. Completely moronic advice.
The software itself quite sucks, there are actually very few things you can actually program, seemed to be more of a gadget feature to me than a real programming thing. You need to restart the controller after each mod. You cannot do any mod on the fly, and there is basically no information provided on the software regarding the controller current status (actual operating voltage, temperatures, actual current consumption, hall sensor position, throttle voltage... nothing). The slide regen can only be set up to 20% of max power, which, on my quite heavy bike, translates into no regen feeling at all. It is not fool proof either, since one time after a wrong set up of the throttle voltage, the bike went full speed directly after power up. Pretty scary. This never happened on the sabvoton, no matter what stupid parameters I ever entered.
On the Sabvoton, you need to find out each time which port your controller is connected to, before trying to connect. It is pretty easy, just need to check in "printers and devices", but a bit annoying, it would be better if this step was automated just like it is on the Kelly. This is pretty much the only downside of this software, since otherwise it is pretty nice. Lots of parameters can be modified, in real time (you just click "OK" and then the new parameter will work instantly, no need to restart), it provides a lot of useful real time information, like operating voltage, throttle voltage, current consumption, motor rpm, etc. You can set up a new motor in a matter of seconds, just using the "Hall sensor test" mode, the regen settings can be set up very high (100A max if I recall correctly), which is awesome on my machine. It also have a lot of nice features such as the field weakening, which allows you to reach a greater speed, at the cost of efficiency. The user interface could be a bit clearer with explanations on what each parameter is actually doing, but this is not much better on the Kelly software anyway.
Driving experience:
-You have to understand here that those two controllers have a very different technology. Square wave for the Kelly and Sinewave for the sabvoton. Kelly is also doing square wave controllers, but I never have the opportunity to own one so far.
Kelly: the start up is quite rough from 0-5km/h, lots of vibrations, lots of horrible noise like the thing is gonna explode. This is normal on square wave controllers, but not really nice. The start up torque is good, given the weight of my machine. Once passed 5kmh, and until about 30km/h, the motor sound is really fun and nice, sounds almost like a Formula one engine. There is plenty of torque and it doesn't take much time to reach 30. Passed that speed, the sound becomes less audible and the torque seems to decrease, or at least to reach a flat curve, until you reach the top speed, which on my machine was 97km/h. On deceleration, the slide regen was not noticeable since it can only be set up to a very low value. I don't use the regenerative breaking so I cannot say if this works fine, but I saw in the software that it can be set to 50% of controller max power, which is not actually very high too.
Sabvoton: Very smooth start, no vibration, no noise whasoever. Extremely easy to control, it feels like a gas powered engine. The total absence of noise is pretty much amazing. The start up torque from 0-20kmh feels a tiny bit lower than the Kelly, but passed this point the power and torque seem to go up more and more, until about 70km/h where it starts to hit the top of the curve. I reached 115kmh without the flux weakening enabled, in less time that what I needed to reach 97kmh with the Kelly. The regen was set up to 75A, and it feels pretty strong, works well. I really enjoyed the ride with this controller, The only thing I actually liked on the Kelly was the sound from 5-30km/h. To me the Sabvoton feeled far superior.
Conclusion:
Well, in my opinion, at least between these two controllers, the Sabvoton is the clear winner. But my test was not at all imparial, the kelly is rated at 120V and was only running at 72V, so it is potentially way more powerful than the sabvoton. So in terms of pure power, I think the kelly would be the clear winner with the appropriate battery.
In terms of driving feeling, the Sabvoton is far superior because much smoother and has a very nice throttle feeling, without any lag.
In terms of hardware design and safety, the Sabvoton is better
In terms of software, the Sabvoton if way better.
So for me, sabvoton is the best. I just wish they do an even more powerful version of their awesome controllers.