I just got the Sigelei 150 and a Subtank Mini the other day. I have no need for anything close to 150W, but since it uses replaceable 18650's, it should last me a while, and it will be an option if I ever do. The combo works great and produces much better vapor and flavor than my previous rig (MVP 2.0 and nautilus).
I have a couple mech mods and several RDA's en route from China (my first dripping experience - wish me luck), that I will be using at home, but for use at the office and in the car, the Sig/Sub is a great option. Plus the Subtank Mini actually doubles at an RBT (RTA?) right out of the box. More options are always a good thing.