Hmmm... After all the hate on the 1911? First your partner in crime and now you?
I prefer a shorter Commander size as well. That being said, I am just switching from a Ranger II to a Trojan. Reasons are pretty much the same as previously mentioned. Better sight radius, recoil, etc. I found at the Nationals and several recent matches I was having a hard time making longer shots with the Ranger. I have since switched to the Trojan and am making the longer shots similar to what I had been missing albeit in practice.
You may want to think about .40 instead of 9mm. The reason for this is that you have the option of going major or minor depending on the match. Also you have the option of shooting standard in major should you be the only classic competitor.
The biggest issue for 9mm and .40 minor is finding good mags. I have had no issues since I have broken in my Tripp fit in the box magazines. At first I did have some problems with the bullets loading - would jam on the loading gate. But for now no issues at least recently.
If you are stuck on a Commander length, then would suggest holding out for a RangerII if you can. They quite frequently show up on the EE.
Let me know if you have any questions.