I've played a DW 9BS on and off over decades on a small bore horn, but am now experimenting with some Josef Klier pieces. The main issue that I have with Wicks is not the rim, which is on the flat side, it's that the smaller models have little in common with each other in the way that they play. The 9BS has a much more open backbore than the 10Cs or 7CS and plays bigger IMO.
Each one is a piece unto itself, made for a specific purpose (?), unlike say the JK range where the width and depth is selectable and the throat and backbore increase with the cup depth. Of course with this system, there are going to be outliers, pieces that rarely get used.
If you try a DW and it really works for you, that's great. But if you want an incremental change I wouldn't go down that route.
I've bought three JK pieces so far and they're all usable, one in particular hits the spot, and overall the cost has been less than going down a modular route.
8E, 8D, 7E, and I might go with a 7D if I start using my 3B again.
http://josefklier.de/mouthpieces/trombone/?lang=en