I bought the Carvex with one battery 15v, and wish I'd gotten two as it doesn't last very long at all, so it's going to be first really and effective setup when I buy another tool that uses a compatible battery, I've been waffling on getting the 18 DRC drill with the to 4.2 Ah batteries, but other purchases keep getting in the way. Sometime soon I will have to make a decision, lately I've speculated on getting the C15 4.2 Ah set, and combining it with a TI impact, this way I'd have three 15v compatible tools...
I love the freedom of movement with the cordless jigsaw though, outside use and you can do away with the dust collection...or even better use a vacumn at the work table..