No it's not. I have Muse HD with build 2358.
This one was bought from Finnish online bookstore Elisa Kirja (
https://elisa.fi/kirja). They suddenly started to offer Odyssey Frontlight 2 (99€) Muse Frontlight (109€) and Muse HD (139€). I recently broke my Odyssey HD and though of getting Frontlight 2 as a replacement, but they were sold out in few days (don't know how many they had), so went for Muse HD instead. Seems to be a working device. I had my books on sd-card, so after authorizing the device with my Adobe ID all my previous books were readable.
DRM causes real trouble for me (Linux user), so have been considering stripping it off. Haven't bothered yet as it seems to work after you get fist steps done.