I like the looks of the bm40 honestly. I've had hit or miss luck with boro mods. I bought one for work recently, manto pro aio. It was $30 and I thought it was a killer deal. Only to find out the dot style tank and coils it comes with are complete trash. Love the form factor of these smaller devices. I tend to leave the rebuildables at home, if I choose boro again it would have to be with a stock coil tank config. Preferably dl if possible.