It really depends on how ocd you are. You could easily buy the projectors from TRS and install as is with no problem. You do have to open the headlight and cut a little bit around the mounts so they will fit but that part is easy. I did however get the projectors, install clear lenses, and tune the output to straighten out the cutoff which took time. I also spent a good amount of time installing the Fx-r's and testing the output, installing the Acura TL projectors and trying to make them fit, and ultimately settling on the rx350. The TL required major cutting to the mounting surface of the headlight just to fit it in the housing which ultimately made the mounting surface to weak and I busted some mounting poles off.
Long story short is it all depends if your happy with a stock output or tuning it to your liking.