Yes, I have been thinking about the Contax N as well and shoot a few questions to him. The reply seems promising as Sony also claims the A7 has better hybrid AF algorithm. It remains to be seen what Metabone can do with their next generation of adapter. Some of the Contax N lenses are really good and I will hold on to mine. Of course it is probably too much of a hassle for a new user to embark on it.
"With adapter firmware version 18 (May 2013), autofocus has been enabled for NEX-5R and NEX-6, for all lenses with distance information support (which includes all Contax N lenses) even though f/1.4 lenses such as your Planar 85/1.4 may still not focus accurately. We have found the NEX-5R and NEX-6 to have an improved AF algorithm over previous models which makes accuracy with legacy lenses designed for phase-detect DSLRs much better than before, and also Metabones' own AF accuracy has improved."
IMO, the Sony A7 is probably better suited for those who want to use smaller lenses. If you are using big lenses, there is probably less need to look for a smaller body anyway.