Sunrise Express – Smoking Room by the Shower

My partner and I were able to book a Twin Room on the Sunrise Express from Izumoshi to Tokyo, but the only room we could get was the smoking room next to the showers (car 4, room 4). Our trip is flexible where we could try to go for a new room another day (or, more likely since I doubt we can get lucky and get a room the second time, go for two Single Second-Class Rooms – maybe on the top floor so we can have the rounded windows).

My question that I need help with, if anyone has experience:

1. Are the smoking rooms bad? Most of the reddit posts I've been able to find say no, but my partner is sensitive.
2. I've read the rooms are sound-insulated, but does anyone have any experience next to the shower? I can't imagine it ISN'T loud.
3. If you had to choose between a smoking twin room next to the showers or a single room with a better window, which would you choose?

I'm leaning towards the two single rooms (if we can get them), but would appreciate additional opinions.

Thanks!