Some of them are different. The tekin battery doctor 8.0, which is the one I have and Promatch recommends, drops the voltage to .5 per cell before it cuts off. Some of the others are a little higher and some lower.
The Much More is differant then the equalizer trays that Fordplay listed, They are used more for AFTER you discharge your pack. Either after your run or to discarge a ful pack. The intergy will dicharge your pack fully, but isn't constent. Where the Much More is a discharger and an equalizer. Even without the link the Much More is better then the DPD unless you want to wait forever for your pack to discharge. I have had both at the same time.