I don't know much about sienna sinks, but there are a lot of Ticor fans here.

We have a Ticor S405D, the model w/two sinks. We've been using it for almost two years now and are still very pleased with it. The large bowl, which I think is comparable to the single bowl in the S405, has been large enough for all our needs...cookie sheets, roasting pans, refrigerator bins, etc.

We love the grids that came with it as well. For example, they keep things off the bottom of the sink so pots/dishes do not block the drain holes, when emptying pasta into a colander, the water does not backup into the colander, it's very easy to rinse the sink around dishes, if you care, there's less scratching of the bottom of the sink.

The sound deadening works so there's no ringing/loud noise when running water, etc.

Not sure what else to tell you!