When seen side by side, I think the pants look better with the larger black and white piping, but I confess to not noticing the different pants during the game.
I would be willing to bet the smaller-piping pants are cheaper...and that said, I suspect the changes we've noticed are financially driven - such as the single piping pants, the replacement of the Pirates video with the voice-over intro - and perhaps other changes yet to come. They lowered ticket prices and parking prices, so this is where they are cutting costs. Perhaps they dropped the Pirates video so they don't have to pay royalties on the music. Booooooo.
Brooks & Co. may have been betting that fans won't notice the difference, or if they do, they won't care...Not on this board.