I'm confused by this. Are you currently unable to buy a seat in business class Venture cars at all, or are you referring to an upcoming change that would allow someone to book a specific seat assignment in the Venture business car?
I'm about to give the Wolverine a try between Chicago and Detroit and not too impressed by the Venture coach seats, so I'm wondering if I should spring for business class given that the trip is over 5 hours?
I did this trip a few years ago in the old business car and found it to be a stuffy and noisy (from conversations) ride, whereas a walk through the train revealed a more spacious and quiet environment in the coach cars. The business class seats were so few that there wasn't an option to escape annoying chit chats who would not shut up for a second, whereas there at least is a quiet car option in coach.
Also on the return leg, I'll be taking the late afternoon train going from Dearborn, MI to Chicago, and as a single traveler, without a specific seat assignment in the business car I know that I'll never snag one of the single seats given that there are something like three stations before the train gets to Dearborn, and I'd probably have a better chance of sitting by myself in coach with an empty seat beside me.