Staying at Marco&Alina was a great choice.
First of all, the space is very clean and very well organize. You can find anything you need there. The place is located in a strategic zone, because you can find plenty of restaurants that have lower prices then other zones and very fresh and tasty food. There is also a pub nearby that serves like ~25 types of beers, which i recommand.
Secony, Alina was a great host. She spended like 1h explaining and drawing us what to visit and how to take the most from our 3 day trip. She also gave us a lot of tips like where we can find best food, best gelato, etc. She gave us everything we need and she responded promptly every time we needed. I surely recommand this place for staying in Venice.