I've looked into Kinetico and they seem to be good units but now there are several that also regenerate on demand. IIRC, the big advantage to the Kinetico is they have two resin bead tanks and one salt tank and they switch from one bead tank to the other so even while regenerating you still have a normal supply of soft water. At the time they were the only ones that actually measured how much water went through them and regenerated accordingly. No more need for a "vacation" setting. Now most companies offer a few units that regenerate as required.
You shouldn't have to "drain" anything, tankwise. The salt, or brine, tank, only has some water in it during the regeneration process and the rest of the time just salt. The resin bead tanks will have water that's being softened in them, but they're not that big and shouldn't need to be "drained". Depending on the age of the unit, they may need the resin beads replaced.
Probably your best bet is to find a Kinetico dealer and see if he has a manual and can help you out on operation and hook-up. You might also "entice" him by telling him that when you get the unit in you'll try to have him come over and give it a checkup or service.
John Stricker