Ok, Rolandfan, you are right, I also had liked Rolands. But...
EM-55 has more Mbs, yes, but for much more sounds. It must be considered.
In Em55 you can't edit styles: only mute parts, but not change volume or voices for them. And you have only two "direct" variations for style (you have more no direct variations).
About sounds, a month ago I played EM-55, and I rememeber I didn't like its piano voice. But it was grand piano voice, the first voice in kb. Perhaps there are more and better piano voices hidden (Roland uses a no logical form to order voices in VA series).
About styles, EM55 it has few styles. Although Roland styles are richer than yamaha styles, which always sound (for my ears) a little "metronomic".
At the end, they are two differente kbs, but specially two different ways to make arrangers. Rolands have a different philosophy wich you may like or not.
Cheers