We stayed there summer 2009 and it's great, as long as you know what to expect.
We stayed in the actual Residenza Favaro, which is down a little tiny alley and there is no reception or facilities at the building - just rooms. That's fine - if you know that.
The room was tired and we were a little worried about using the electrical sockets - but despite all of that it's brilliant because of where it is. It's a short two min stroll to Saint Mark's Square - right on the poshest street in Venice with all the designer shops. Find the Bulgari jewellery shop, and you're there (well, down an alley).
Views non existent, but you can get air in the room. It's nice a dark, so fairly cool (marble stairs keep it all cool too).
Be prepared to firstly locate the premises, then you ring the bell and they either direct you to the other hotel where there is a reception - or a chap will come and meet you in five minutes. You might have to traipse to the other hotel to sort out paperwork etc.
If you turn up to Venice with heavy suitcases - you're going to struggle - pack light, there's a lot of walking from any ferry stops and there's plenty of bridges with steps.