The channels have to present their data in the same layout as the native Plex library, so the interface is consistent. It automatically downloads artwork and metadata for movies and TV shows in your library based on their filenames, and there are many high-quality channels (plugins for streaming content) that you can install right inside the client. It can handle almost any file format (without installing extra codecs), unlike Front Row, and you can have it watch any folder on your machine (or network), not just the ~/Movies, ~/Videos and iTunes. But the current Plex version has a VERY clean interface and works great with the Apple Remote.

I always disliked the visual clutter of XBMC and Boxee, and even earlier Plex versions. In terms of user experience, Plex is the closest thing to Snow Leopard's Front Row. Since then, Plex has won me over, especially with the huge progress made in the last year or so.

I've been using and testing different media center apps for years, and, like you, stuck with Front Row until Lion came out, because nothing else felt quite right.

Plex airplay