He probably means "are they effective" .. I had one..briefly..sent it back..b/c thier was a problem with it..and also decided I didnt want to take the time to relearn all the differnt configs..but I do think/know peeps are using them..as I have gotten killed with peeps I could guarantee were using them.. They will run between 460-80 typically..
It would be helpful in answering your question if I knew what type of mods you're thinking about. Back paddles, trigger stops, etc. What ones are you speaking about?