The close focus distance of the 45P is 0.45m, same as most other 50mm lenses, so close focus distance is average for this focal length. The older 45GN has a rather long 0.8m close focus limit, due to the GN mechanism. Early 45GNs have 9 aperture blades, but that later changed to 7.
I bought a 45P with my FM3a. Although I don't have big hands I found it too small for my liking - the focus and aperture rings are very narrow and there is no grab ring so it's not so easy to take on and off the camera. When I need a compact standard lens I use the Japanese "pancake" 50/1.8 which is based on the series-E lens but focuses to 0.45m instead of 0.6m. It's still very small but there is more real estate on the barrel to make handling easier. It's also over a stop faster which is useful.
My favourite 50mm is the AI 50/1.8. It has a different optical design from the Series-E/pancake/AF versions, sharpness is possibly better and background rendition is smoother, becoming harsh only towards the corners. The focus throw is also longer. It has a full size barrel so handling is even better, although it is still compact compared to the current AFS models.
If close focusing is important, the AIS 55/2.8 micro is worthy of consideration. The AI 55/3.5 is also excellent but f/3.5 is starting to feel too slow for this focal length, and I'm not a fan of the bokeh produced by 6-blade apertures. The AIS 55/2.8 feels fast enough (just) to be used as a general purpose lens, and it has a nicer 7 blade aperture.
