I bought a brand new 645 when they first came out.I didn't like the 45 acp round until I fired it out of a 1911. I traded the 645 in towards a 1911 and never looked back. The 645 worked fine enough,and it looked good to see a semi auto with a factory red ramp.But it sat high in the hand due to poor grip design that they quickly corrected in the 4506.I found it not to be a natural pointer like the 1911.