The good news, as already expressed, is that you will get more accurate and consustent exposures in manual.
I shoot M6s/MPs only, with EOS for when I need an SLR. In B&W I consistently get better exposures with the Ms.
I walk around and set exposure based on shadows and don't give a damn about highlights. They don't generally matter much unless you are in extreme scenarios. Only when I see a change in shadow values and where I want them do I change exposure. So for example: I am walking about in the shade of a building and have the exposure set. As I round the corner of the building I see a person I want to photograph. They are still in a block of shade at the base of the building but in the distance the sun is striking the earth and the tops of other buildings. I do not change exposure as my shadow needs are the same. I deal with the increased density elsewhere with contrast, flashing etc in the darkroom or by printing the image down and dodging the person in the shade.
In the above scenario, AE would have violently reacted to the sun striking the tops of buildings, the bright sky, sunlit ground etc, set a much faster exposure and my subject would have been grossly under exposued. This is because most meters work for highlights to ensure good exposure with trannie film.
With practice, you get really, really good at this. It works miles better for snap shooting than AE (because you have pre-set a good exposure and anticipated, rather than let the meter set the exposure in the split second you fire.... and they are often fooled). When you have the time for a given scene you can make small tweaks before shooting and get things perfect.
After a few years shooting manual Ms I was amazed to look back over my Eos negs and see how poor they were in exposure consistency and just how many snap shots I lost due to underexposed shadows with the meter fooled by bright light elsewhere in the frame.
I am now shooting my EOS again for portraits and I am having to apply my M methodology to bring the exposures up to the same standard. In AE, no matter what mode I use, I am just not as accurate if I leave it to do all the work. Now I use centre weighted or spot metering with AE lock when required, with the EOS. Still prefer my Ms tho. it just seems to do less interpreting and more straigh metering so when I check the exposure I know what it is based on. The M has no brain and so allows me to apply mine without having to second guess anything!