I've not used WL past v4 (still use it for playback of digital files), so a lot may have changed. Fundamentally, Sequoia was 'further along' imo, seven years ago when I switched, but I'm certainly willing to give it a look.
Somehow I doubt I'll make the switch, but I'd really love to get out of the Windows environment, and from the little I've read / heard regarding v7, WL is the first option to come along that may be a truly viable alternative...