My main problem is that I seldom practice! I usually just try and play something and when you are playing you try and gloss over the mistakes. This means that at some point I have to go back and iron out all the issues. As mentioned above, it is easier to get it right first time. (Must make a note!)
Metronomes: I can see all sides on this. I do not often use one but every now and then they are useful. I can remember trying to perfect Chopin's Fantasie Impromptu, which has three against four for much of the time. I got to the point where I could play that part in a somewhat "lumpy" fashion then I used the metronome to help me slow it down. When I could play it really slowly and evenly, I found it easy to play at the proper speed. YMMV, as we say on the Internet.
Another use for a metronome is for a long piece when you suspect that you are not playing at the same rate all the way through. I know some professional organists who would benefit. They speed up unnecessarily and it really bugs me! Then, of course, when you have it straightened out and it now sounds like an expressionless MIDI file, you have to put all the expression back. It depends what you find easier, I guess.
I have not noticed any random speed variations from any of our ContreBombarders yet. It just shows the quality of organist that Hauptwerk attracts.
Regards,