You couldn’t go wrong with either one. All these homes are big and situated on large lots.
The Santa Valey homes (Bel Etage/Savenna/Salviati) all share similar floor plans (built by the same builder – Colrich). The real difference is that the Salviati homes tend to have bigger lots than the other two.
As far as traffic noise is concerned, I can’t speak for either Bel Etage or Savenna, but it’s not an issue with Salviati.
Personally, if I had a choice between Ivy Gate and Santa Fe Valley I would pick Ivy Gate. The planned transit station and church across from the fire station is a concern.
