I won't beat around the bush, ( ) poly bushes will certainly make the car less comfortable. But then so do coilovers, so just really depends on what you're after. Will you be hooning it every chance you get or just normal daily driving? If normal daily driving, I would recommend poly rtabs and BMW 3.0L M3 eccentric wishbone bushes.

Something to consider though is that the poly bushes are lifetime, so would be nice to know you won't be replacing them again anytime soon. That's one of the reason I powerflex'd everything!