We had booked (and paid) in advance before seeing some of the poor reviews on TripAdvisor, so we were anxious about what we would find when we arrived. But we were pleasantly surprised that our double room was large, the bathroom was clean and the breakfasts at 6 euros each were better and cost less than elsewhere locally.
Nothing in Venice was cheap, so we got what we paid for. The location is really great - only a couple of minutes from the waterfront at San Zaccaria and only 5 minutes from the Doges' Palace and St Mark's square.
The hotel decor was tired and there is no lift/elevator, so I hesitate to recommend the Hotel Lux - but if you are on budget, have no mobility issues and want to stay near some of Venice's main tourist attractions then this may be the place for you.