The concept is interesting: sleep in a boat on the Danube. That alone is worth to experience. That being said, the comfort on a boat is usually somewhat limited. The room itself is quite big, but the bathroom is cramped. My room was on the south side, which means you have a relaxing view on the Danube. The disadvantage is that it heats up in the sun and there is only a fan, no air conditioning. Beware of that if heat is a problem for you.
Staff is friendly and helpful. The wifi works great and the TV has Netflix. The breakfast is on the top floor with an amazing view. The variety of food is ok for a quick bite, except for no bread being offered, just toast. So plan a whole meat later in the old town of Bratislava.
In conclusion, it's worth a stay for a day or two. Just don't expect any luxuries.