I adore my BBH. It has changed my life.
I have very thick, coarse, dry hair. When left to dry naturally, it ends up like hay. Never silky and floppy. For example, if you were to take a small handful and pull it between two fingers, it wouldn't flip down, it would stick out straight like hay. In other words, horrible hair.
My BBH has changed everything. I now have nice, smooth, swishy, styled hair.
I will state, however, that I am on my third one...! I don't use it every day - probably every 2-3 days, i.e. as often as I wash it (when your hair's as dry as mine, every day washing is a no go).
My first 2 BBHs lasted aout 18 months each before burning out. In all honesty, I think that's pretty crap, especially as I don't use it every day. However, given its life-changing qualities, I have automatically replaced it each time.
I'm in NZ and we can't seem to get them here. I had to have my brother send me one from London when the last one went kaput. Had to, you understand, as life without my BBH is inconceivable. He then got off the plane at Christmas time, and presented me with another one, for when this one inevitably burns out. 
I don't care that they're not exactly brilliant made, only have an 18-month life span, and are probably massively over-priced. They're indispensable, a far as I'm concerned.
Oh, and I'm on a 42 at the moment (previous two were 50s) - I think the bigger one is actually better, even though I only have a short bob. Purely because my hair is so coarse/wiry.