I have a screwed up back and bought the Rush and it's the best decision ever. The energy transfer is nuts and with not being able to generate huge amounts of power on my break, this cue smashes the rack constantly.
For my money I'd give the Cuetec Breach a go.A little bit cheaper nd more power than the BK Rush, plus you can actually jump with it full-cue. Having had the BK Rush before the Breach I wouldn't go back.