After much research, I ordered a 4.15 CuFt for my Metro HP today. I looked at the Exmark bag style,and just didn't like the way it attaches and dumps. It also looks pretty small.
I called Accelerator, and Peter himself answered the phone. He was very helpful, and put me in touch with the distributor who informed me that my local dealer could get the catcher.
Can't wait until it gets here.
I'll report back after it arrives.