I have the original 645 plus a 645 Super with the AE finder and motor drive grip. They are both great cameras. I've been using the 80 f/2.8, the 45 f/2.8 and the 150 f/4.0. The 150 is a great lens; even the earliest version f/4.0 (which I have) is a winner. If you are looking to round out your system, that might be your next lens. It's also very affordable.