Hi there,
I was just on SOF in March. I was on my own and was in a twin share.
You have no guarantee on that you'll get the quad to yourselves. The boat is spacious and nice. I didn't go into the quad shares to see the layout of the bathroom. However, from a woman who was on our trip, I know that two of the bunks run the length of the boat and the other two run the width (i.e., are perpendicular to the other bunks). She needed to be in one type to avoid seasickness which is how that came up.
Clearly you don't spend that much time in the rooms but you will be down there. You will need to co-ordinate the showers/toilet usage. I know that each cabin has its own hot water supply so a quad is likely to go through the hot water faster.
I don't know how much space there is for storage or to hang towels and other things to dry. I do like to try to get towels and clothing dry but that's me.
I'd probably go with the twin/double as you'll have a bit more privacy. However, I wouldn't go for the suites. They are on the top deck towards the bow and thus get the roughest ride!
I have shared on many liveaboards but always with one other person rather than the quad option (which has been available at times). It's really down to your perference, but it sounds like your hubby might not like that.
