There are over 200 such pieces available for free download from Ambisonia.com. All these can be downloaded either in B-Format (for which you will need a decoder), or in "G-Format" (decoded for four speakers arranged in a square). G-Format is just speaker feeds minus some fancy stuff like shelf filtering..... My problem with UHJ (BHJ) is I just think they went too far with the compatibility for center back and such in mono - phase shifts are just 'unpleasant' for me when I hear them like CF in UHJ. Now full G-Format Ambisonic, like the first demo DTS CD I have from Jeffrey Silberman sounds incredible - I can hear people talking all around and can even 'place' them in distance. 2-channel UHJ - especially decoded - just sounds like a phase-y mess to me. But G-Format from B-Format - WOW!
Yes, the designers of two-channel UHJ tried to do a lot of things at once: Mono compatibility, stereo compatibility, and good decoding to surround. Note that you can obtain the first two things from B-Format by producing either Blumlein Mid-Side or Blumlein Crossed Pair stereo feeds. These conversions are described in the Xiph Wiki. These have the advantage of no phase shifts whatsover. Their disadvantage is that they cannot be decoded back to surround sound.
It seems you can do any two of the three things really well.