8 rnd or 10 rnds is still 4 mags per stage, but stage design will dictate where's best position for mag change, which can make 10 rnd mags a 5 mag stage and a SS a 5 mag stage, or 6 for that matter, also depending on if there's some tight shots or plates, where you suspect an extra rnd or two for back up will come in handy and not screw up your mag change plan, or not... again stage design makes big difference on what you'll plan to do...and what really will happens, maybe another...
Yes, extra rnds with less recoil can be handy...
buuut, on the other hand, most of us (not Mike B, or like him) will drop lots of points in a match, and and those points (mostly level 2's and even more so in a level 3 match) will hurt us more than the extra few seconds saved, on only those few stages where the extra rnds came in handy.
don't forget, some stages will work just fine with 8 rnds, not every stage in match would have been a negative for 8 rnd'rs.
e.g. 2 provincials, I had misfortune of my ammo juuuuuuuust barely making major (not really low to give me any real advantage, maybe better if it was, who knows) and my points lost due to being scored minor, was at one, over 100 pts, and at another approx. 70+ points (guess i shot better at this one), my point is that those points put me at 32place and another, 25 th... both of those could have been around 12- 16 overal in std div.
oh well, say la vie... sh!t happens..
I don't think if went in with 9mm, the extra few seconds saved on only half the stages, would of made such a difference in overall results... as losing these # of points... again relative... but an example, none the less.
Yes, I'm not the best ipsc shooter out there, but overall, I do o.k. and have lots of fun...
so, would have I shot more accurate if i was shooting much softer 9mm out of a colt 1911 ?
Dont know, but in the heat of the game when the Beep goes off, we all probably push harder and faster than we should and drop more points then we should...
Are you going to really practise seriously and be a great shot ? if so, get 9mm 1911.
or are you going to casually practise and shoot some matches and have fun, but hope to somehow still be competative (like me, still dreaming), then shoot major...the extra points may come in handy...
I believe the average ipsc shooter will not shoot any faster or more accurate cause of the 9mm factor... not if they're familiar with their gun enough to handle the recoil & shoot it well and smooth
I probably didn't make any sense, but if anyone thinks I did, you're as wacked as me..lol
I remember back in the day when I shot .45 with semi-wads, those crisp round holes would catch the edge of plates or the tears off the D score to save my ass

.... bigger is better...
Closing notes, there's pros and cons on both arguements...if you have a 9mm in 1911, then stick with it and save on ammo too...
if you have a .45, use that...buy as much in bulk to keep cost down,
if buying new, I say go with .40 ... shoot in classic and std... if so choose to.