I too find it interesting when "brand inversion" occurs...the rates at the limited-service brands jump higher than the full-service brand. I've seen it most with Marriott but also some with Hilton.

I always just chalked it up to very localized demand. I see it most on the weekends, perhaps because a smaller number of roadtrippers can fill a Fairfield Inn whereas a large Marriott is much more empty. I have always thought of FI as a "by the freeway" brand (like Hampton Inn) and associate it with roadtrippers, mainly leisure travelers.

I favor hotels with free breakfast no matter whether I'm traveling solo or with family, whether for work or pleasure. It just irritates me to spend money on breakfast or wifi, even if it's the client's money.