Nice UI yes, but UI isnt anything compared to functionality. So yes be proud of it but dont be more proud of it than the emulator. Looks like merely skinning to me, which really isnt that special. Any emu could do it, but it doesnt make the emu persorm any better.
there are few msx emulators that works good, I used paramsx a little buggy, but this bluemsx seems very good, the sound is good, support for savestates and other stuff, the speed it's adjustable