The domain redirection from exch.cx to exch.pw will be reverted within 2 days, leaving three separate domains operable without redirection: exch.cx, exch.pw and exch.is (TBD). We are also in a process of acquisition of some more presentable domain name which will be announced once complete.
Will you also create a vanity .onion name? Something that's easy to remember and very hard to reproduce. I think the way to do this is generate many vanity .onion domains, and hand-pick one that has "something extra" that rolls off the tongue.