All the monts our way run 9/42, had mine 8mnths ,used at min 4hrs a week and no probs with the guard/slipper as yet.+ they are cheap enough/easy enough to replace when/if needed. I think you will find the benefit of a 9 front outways the worry of slipper wear.

I know a lot of people that really like a 10/43 over the 9/41. Good compromise in my opinion.

I had 10/43 from the previous owner and it was quite good. Not sure I would want a 9 on the front...

I may be a bit eccentric but I like and ride stock gearing...

Don't you need to remove the swinging arm to replace the slipper guard?