You mean the old three-way ones with LEDs? If so, I tried the non-passthrough versions - first kit thing I ever ordered from GV, in fact. I actually liked them a lot, but I killed them both. One fell victim to a short, and the other fell hard on concrete. Both started acting funky after that - lights would go on randomly, charge levels would jump around... It was probably just LEDs acting up, but I stopped using them just in case.
I liked them then. But I'm really liking the RR Stardust at around 4 V, plus or minus .2, so it would be too low for me at this point, except for a few juices that are better at low power. I still use the dongle that came in that Vornado kit, and even the top setting on that is not quite enough...
I'm really hoping for a Twist passthrough, eventually. That would be really nice.
Have you tried any of the low voltage ego vv? They start arround 2.6-2.8v. They are very nice for lower voltage devices and still have top voltage of 3.7v. My last one lasted for 3 months till I decided to clean a stardust with it still attached.
Note to self never clean anything while half asleep