There is absolutely nothing wrong with a "good" model B. I ran one for years on my '52 216. I even let the truck sit in the driveway for 15 years without ever starting it. One day I got fired up to do something with that rust heap, so I put five gallons in the tank and as soon as the gas got to the carb, it started right up and purred like a kitten just like it did 15 years prior.
Lets see you do that with a Carter YF. The accelerator pump diaphragm will not respond. The Model B has a leather pump and just needs to be wet to work.
Having said that about the Carter, I find that they perform better than a "good" model B. No dead spots upon acceleration is one thing that I notice.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission