"I don't think the 307Win or the 308 Marlin express are ever going to catch on."
In the Marlin, the .307 is dangerous. The 308MX has caught on, and is selling real well. It would have done even better if they hadn't offered the XLR version first. The blued version looks 100 times better, and the shorter barrel makes it a woods rifle.
While I love my .35 Remington, I disagree about the need for a rim. IMO all leveraction cartridges should have a rim. In fact, almost all good rifle cartridges do have a rim.