IMHO, Media Center 11.1 is the world's best
music jukebox. Its name could as well be Media Jukebox 11.1.
(A brief history lesson: The "Media Center" name was introduced mainly for marketing reasons. When JRiver released v.9 they renamed the program as Media Center. They removed some functions from MJ8 (like TV) and left it as an entry level product. At that time they probably had plans to introduce newer Jukebox products, but I suppose the plans have changed. The history is available at this forum.)The product comparison table JRiver has published doesn't tell how good the audio functions are. Media Jukebox is still a good program, but Media Center has hundreds of audio related enhancements and new functions. You really should try MC11.1 too.
Scot Thompson has made an excellent FLAC plugin set for MC (encoder and decoder), but unfortunately they are not for MJ8.
Though, I guess no one has tried the older v1.3 decoder plugin that works with MC10. I think MC10, MC9.x and MJ8 used quite similar plugin interfaces (I may be wrong in this) so you could try the v. 1.3 decoder plugin with MJ8. Scot's plugin page:
http://members.cox.net/scot.thompson/.
The Media Center plugins download page has also an older FLAC input plugin (made by oblong) for MC9.1 and newer:
http://accessories.jrmediacenter.com/mediacenter/accessories.php.