[ I've relied heavily on aperature priority it at times and I just don't know if not having that option is a significant handicap for a total leica beginner. I know this a hard thing to advise on, but if anyone has any thoughts I'd so appreciate it. ] >
Hi,
I understand your situation totally! I started with an M6 and loved it, a fantastic camera. However, I switched to the M7 soon after it came out because I really missed having aperture-priority AE. I use the AE as second nature - find the middle-grey area of the scene, lock exposure, recompose and shoot. I find my exposures are MUCH more consistent than when I shot with the M6, and I am much more likely to bring the M on a shoot where I know I'll be rushed, or need the highest degree of spontaneity. Even if the light is variable or inconsistent, I can rely on the M7.
If you shoot lenient film (negative films) and / or in consistent lighting, then the manual exposure of the MP is great, hardly a need for the automation of the M7. However, I like to shoot slide film in highly variable conditions, and I tended to miss exposure too often with the M6. The M7 and my simple AE-lock system works wonders - and the M7 tells you the selected shutter speed in the VF, so you can readily see if you can hold the shot. Also, I tend to shoot wide-open, or close to it, so I don't futz with the aperture much.
Others are able to nail the exposure with the M6 (or an M4 with no meter for that matter!) with no problem, but I was never able to get as reliable as I would have liked - I guess that is what I get for learning with an OM-2 (aperture-preferred AE is awesome on that camera too).
Another note: if you are new to rangefinders, the focusing switch from an SLR is significant, and having one less thing to worry about (metering) could help you concentrate on focusing accurately. It took me many months to get used to focusing the M6 such that I could get what I wanted in sharp focus with an aperture of 1.4 or 2 - it is very different from SLR focusing! Now, focusing is pretty much automatic, metering is (really) automatic, and I get more of the shots I want. It's when I go back to the SLR that I get slowed down
One good note: you cannot really go wrong either way! Both MP and M7 are quite capable cameras, but the M7 can always be used in manual mode, whereas the MP cannot be used in automatic mode. There are the battery issues too - M7 needs 'em more, though I have had success with dead batteries on the M7 too, lucky guessing and a 1/60th shutter speed. Oh, and the TTL flash can come in handy, though it is considered heretical on an M by many (not me, I use my M7 and flash for snapshots all the time).
I hope all this rambling helps in some way. Bottom line, think about how you use cameras, and how you want to use the M. Don't forget that you will take actual pictures, not just fondle the thing!
Best of luck, - marc