I have three reciprocating saws in my box. An 18v cordless DeWalt, a 15 amp corded Milwaukee Super, and an old corded Black & Decker with a saber grip. The Black & Decker only gets used when the saber grip makes the job easier, which isn't very often.
I've had the DeWalt for about four years now I think. Great for when a cordless tool is the best option. Will "cook" a battery if you let the charge get to low and try to push the tool. Run time is pretty low if you are working the tool hard. The tool of choice for putting a fresh cut on the Christmas tree every year. The wife occasionally uses it to prune trees. A medium duty tool.
The Milwaukee Super is a beast of a tool that strikes fear in the hearts of carpenters everywhere. In other words, you can do some serious demo work with it. I've used it to cut cement block and concrete embedded with rebar. Highly recommended.
Both the DeWalt and the Milwaukee Super will cost you about the same. If I could only have one, I'd buy the Milwaukee.
I like Lennox Gold blades for most jobs. If I need a carbide coated blade I usually go with a Bosch.