Our 3 night stay at the Sant Elena was part of a BA package and this previous convent was certainly 'converted' into a rather pleasant hotel, however, although probably much quieter than those in central Venice it is rather out on a limb. There are varying times given to the centre with the hotel literature mentioning a 'stone's throw' and others a 15 minute walk - I think that would need to be a pretty big catapult and some extremely serious power walking! We didn't get to do the walk (the weather was atrocious) but would estimate at least 40 - 50 minutes at a fairly brisk pace and the 5 minute vaporetto ride somewhat nearer 10 - 15 minutes - so much for actual location.
The room was very nice, judging from the notice in the room we were in a Junior Suite with a very comfortable large bed, perfectly adequate bed covers and some seriously comfortable (polyester!) pillows. The room had everything required, with leather sofa, coffee table, controlable air-con TV and free Wi-fi. The only surprising let down was that whoever serviced the room seemed to forget to top up the tea/coffee/sugar for the two days we were there necessitating a trip to Reception to collect. UK tea drinkers beware, you will need to ask for milk jiggers as none provided in the room.
Reception staff were all very helpful as were the waiters in the Valentine's Restaurant. Because the weather was so poor for the time we were in Venice this time we opted to 'eat in' for two of our three nights. We were told that it got very busy and we were advised to book but on the two nights we ate there were no more than ten people and that included the two of us - maybe the rain kept people away! The food, seriously good but like many other Venice 'eateries' not cheap - we calculated that our two nights in cost us with a very reasonably priced bottle of wine and not three courses close on £75.00 each night - that said our third meal at a not overly 'posh' restaurant in Venice away from the touristy bits was close on £65.00 and that was with just a half litre carafe of house wine.
One other point the hotel brochure says that the rooms 'look out over unusual and evocative views' - sadly there appears to be rather high degree of poetic licence here, our's looked out on a rather scruffy building next door and even craning one's neck, there was only a rather run down looking basketball (?) court and a sliver of canal and our room had 3 windows! We couldn't quite work out where the unusual and evocative views could be from any of the hotel windows as it just wasn't in that sort of location.
Would we stay there again - yes, certainly from the quiet location and comfort point of view but in terms of easy access to central Venice not quite so sure.