I wouldn't be without this incredibly useful little box. Built like a tank, very transparent sound when used as intended. There is nothing to dislike. If I lost it, I'd replace it in a flash.
It also works well as a conventional DI placed before the amplifier, However, I normally use this in a slightly strange way. I plug the line output of my preamp into the guitar input which drives the tranformer much harder than my weedy passive pickups alone manage. This gets a great recorded sound with a little added "something"
The other feature it has is a *merge* function. This allows the input and the bypass sockets to both be used as inputs. I think it's meant for keyboards and things, however we use it slightly differently. My band shares a rehearsal room with another band. Sometimes we have a jam session with all the musicians who use the room. We plug both bass amps into the DI using the merge function and send the output to one of the inputs on the recording interface. That way whoever is playing the bass gets recorded on the same channel. That way we can both play our own rigs as we please, and both appear on the recording without having to swap cables about.
Incredibly useful, if you don't have one yet, buy one!