aftermarket MPFI conversion kits any good?

ive been lookin around recently at purchasing (way down the road) one of those "bolt on efi" systems for my 360 thats goin to eventually b put in my 70 dart. they even have different systems, TBI (throttle body injection), MPFI(multi-port fuel injection), TPI(tune port injection) and so on. thot itd be a cool addtion since it would increase reliability, performance an economy. they run anywhere from $1500-5k dependant on what system type, brand, motor, ect you go with

has anyone here used any kind of aftermarket efi on there old mopar? are any of em worth the money or should i not bother? i just like the idea of turn the key n go, no warm up no carb tuning. i do understand that you tune the ECU they send but thats not something u gotta constantly do.

what are your guys' thoughts? personally, i think it is a killer idea! all the great technology of modern equipment under the guise of classic mopar style!