I have that same Torqeedo - the CL1103 CS. I just bought it this summer.
I've only used it 3 or 4 times this season. It is really pretty cool. I only use it to go about a half mile or mile from the marina to the middle of the lake, and then back. It uses about 4% of the battery life to do that. I'm only pushing the boat probably around 3 knots, or maybe a little more. A lot of the trip is through the marina, so I'm not giving it a lot of throttle in general. I have heard if you give it a lot of throttle, it will suck the battery down pretty quickly.
It does have a display that tells you how much battery is left.
I didn't get the long shaft - the regular shaft works fine on my boat. The place I bought it from knew my boat, and said "you don't need the long shaft, by the way."
So far so good. It is funny, other boaters in the marina notice it - when I'm heading out, I get lots of "is that electric?" It is totally, 100% silent, which is a nice side benefit.
Scott