A lot of umbrella prices are somewhat parseable (think a simple-ish decision tree) vs auto and home prices which require reverse engineering rate cards to back into the pricing formulas.

Yes, folks come back at the end of their year. Most of the time their price remains the best (non-issue), when there are better options they switch. Carriers have been great partners so far since we bring them much more business than switches (and when the switches happen it's often because risk management wanted to reduce exposure in that region anyway).