As part of my ongoing downsizing, my new house's bathroom will be smaller, so I'm looking at installing a toilet/sink combo to
- save space,
- reduce construction costs by making the bathroom as small as possible†, and
- reduce my water usage

What did you find you had to change in your behavior when switching to this setup?
Edit: † The bathroom's finished size will be approximately 3' (0.91m) x 6' (1.83m), thus necessitating the combo device or some other equally-compact setup.