They have some their own exclusive content over and above the regular FTA channels available on all other decoders. For the time being, this content is also accessible through other decoders, but expect it to get locked onto the Bamba Tv decoder in due course.
They are the only "terrestrial" provider I know of who offer HD content.
They have a decent web presence where meaningful info is posted, not just the usual social media marketing stuff common with competition.
Cons
They recently pushed an update that screwed up the channel clarity (presumably while tweaking HD channels). I'm not sure if this has since been fixed, but I'd give them the benefit of doubt.
You'll have to contend with the adverts that pop up when you transition between channels. Who knows where else they'll sneak these into?
There's a risk of losing the exclusive content should they fall out with their partners - Virgin Media Limited
That said, I use a Hbox decoder that just works. I can lend it to you for a brief test run if you are interested :-)