I'm new to s&w guns. When reading and looking at the cool short Bbl 45 acp 625 guns are they 2 inch or 2.5 or 3 ?

I see the 3 inch on gun broker but they seem to be 1000.00 range . I assume they are Lew Horton or collector. The pictures I see look like a sp 101 2.5 bbl just dont know. I do understand its measured from the cylinder but just looking at pictures cant tell length.

I also am looking for a JM 625 4" 45 acp and need to ask is the PC 625 4" 45 acp a better gun with more features since they bring more than the jm 625 gun and are special from smith.
I think the 625 JM 4" 45 from reading this sight is a good shooter and fun gun . I read the fourm last night but still not sure.

If you could find or buy either gun would you pay the extra for the PC 625 4" 45 gun ?

Thanks
JON