Thanks to the few folks who replied with experiences at the Prince. I've only had multiple rooms at the Westin once, and while they generally followed the rules with regards to guests in the lounge, for example, they also automatically handed out lounge access to both rooms. Surprised I didn't even have to ask, and it was appreciated.
I have patronized these hotels again, but I would like to check out a LC for at least a night - especially when its so new and the location would spruce things up.
It's good to have me & my guests' expectations set - as I figured, given it's a Japanese LC - that things would generally be by the book, and thus the room I occupy would be upgrade eligible/breakfast/lounge, and the second room may receive an upgrade only if the hotel is particularly full in lower room categories, and may end up with comp breakfast.