I'm also looking at either the 306B or 3010B for my next charger. I have loved my 106B+ but in anticipation of ever increasing battery tech and HV systems I want to upgrade. Right now I only plan to be charging 4-6S too, but the way I see it why not go for the 3010B and have the higher cell capacity there in case you need it, since it only costs a little bit more. Better to have it and not need it than need it and not have it.