To me, it depends on several factors:
1. are you camping or RVing? Many campers just need something to rinse off the grunge, but if you're going sightseeing, you're gong to want a real daily shower.
2. how many people will be staying in the TT?
If it's just you and you're using the TT to go camping, then the wet bath probably won't be a big deal. You can do a quick rinse of the grunge before bed and by morning, the bathroom has dried out.
If you're a couple and both need to shower each day, then you'll most likely find that you're using the toilet and sink while the bathroom is still wet from the showers - and that can be awkward/uncomfortable for some folks.