* The SSD-optimized storage engine is running under the clustering engine. I'm wary of saying 'better' or 'worse' in case of benchmarks, because they're really tricky to do right. We'll be publishing well-researched benchmarks as soon as we can, but it will take time.
* RethinkDB has flexible schemas and a query language that integrates straight into the host programming language and doesn't require string interpolation. As far as clustering goes, RethinkDB is a) really really really easy to use, and b) does a lot of query parallelization and distribution that MySQL cluster doesn't do. The product feels totally different, I think in a good way. The downside, of course, is that rethink is new and it will take some time to work out all the kinks.
* I can't commit to a timeline yet, but yes, absolutely.
I'm impressed that you're taking the time to do proper, well-researched benchmarks. They're really tough to get right. It really comes down to your own specific workload that matters anyways.
This feels new and refreshing, I hope things turn out positively for you.
* RethinkDB has flexible schemas and a query language that integrates straight into the host programming language and doesn't require string interpolation. As far as clustering goes, RethinkDB is a) really really really easy to use, and b) does a lot of query parallelization and distribution that MySQL cluster doesn't do. The product feels totally different, I think in a good way. The downside, of course, is that rethink is new and it will take some time to work out all the kinks.
* I can't commit to a timeline yet, but yes, absolutely.