The Evangelical Movement of Wales runs a site in English and Welsh. The English and Welsh versions run on different domains. Instead of installing two WordPress instances, they use WPML. This way, visitors see different contents in different languages for each domain but site admins manage it as a single site.
The Evangelical Movement of Wales/Mudiad Efengylaidd Cymru is a non-profit Christian organisation working bilingually in Wales. Our site has been operating in Gengo for several months, but we made the switch to WPML after increasing problems with Gengo. The switch was incredibly easy, and took only a few minutes.
We’ve also written a custom plugin that adds a better language switcher as a widget, and a log-in filter which (a) displays the WordPress log-in page in the correct language, and (b) logs in to all domains not just the primary domain.
The site itself uses a customised version of the K2 theme, and several other plugins.