The answer you will get most of the time is "it's not an airbus". In reality, there isn't anything horrible about the 73.
No argument that the bus cockpit is larger, quieter and more comfortable. The 737 flies and performs better. The bus is generally a little less work. I actually prefer the avionics on the 73 over the bus.
I'm coming up on two years and 1,000 hours on the 73, and I'm still having a great time. I'll probably have to go back to the bus, strictly for QOL reasons, but I don't really want to.