Xtra (official) - $2199
UI (PI) - $1899
Audiosg (PI) - $1690
Seems like either go official or just get the cheapest with good reviews. lol.
Besides, UI main guy is now based in London (as per his last year post in MO thread) = equal chance of disappearing as much as audiosg.
Xtra is made in China, vs PI made in USA.