This topic comes up just about every year. There are a bunch of threads. Just type Lewis winch in the search box at the top of this page and click on the little magnifying glass. You will have an evening of reading ahead of you. Good pro/con discussions concerning capstan type winches like the portable winch(Honda powered) and the Simpson Winch (mounts to chainsaw) versus the fixed drum winch=the Lewis.
Personally, I have a Lewis. So far it has pulled 5 moose out of some really nasty places. Despite it's weight and limited drum capacity/cable length, it is an awesome piece of kit.