Well, I have almost all of the guns listed on here, well....just because I like guns, and have been collecting them for a long time.
And.... You owe it to yourself to go to a gun store and just heft a 649-1 Pro Series. You will be amazed at how much better the sights are than your 649. They are Novak sights, and are drift adjustable, but the sight picture is fantastic, and while they are black, when shooting against a dark background, the tritium vial outlines of white give you a three white dot sight picture, and of course in low or no light, the tritium give you a three green dot picture. I shot my departments qualification course this up year with both my Glock 23 and the 640-1 pro, and the 640-1 outshot the Glock. YMMV, but...I think it's ou should heft one in a store, or at a rental range and see for yourself.
If I get a chance, I'll try mine out at some longer distances and see how it does. Longest I've shot it was 25 yards, and it did just fine at that distance (during quals, and under time, at that)!!
I also have the 66 2 1/2", and carried it for many years, and it is a fine choice, but a little heavy for cargo shorts!! But just fine in a pancake style holster. I carried mine on duty in plainclothes and never had a complaint.
Best Regards, Les