What's the big advantages to the Currie unit over a stock 8.8? It doesn't have the extra bearing on the axle side of the pinion gear, which is a big source of the 9" strength. You can set up the third member on the bench, but so what? It's not like you have to do it often. And you can't afford to have a spare on the shelf in case of breakage.
The TrueHi9 must use custom-cut gears, which is probably what adds the cost. If it has the extra bearing, it would be a nice, strong unit, but I'd be leery of buying a differential for which there is only a single source of gears. If they go out of business and you do break something, you're scrod.
But maybe I don't know what I'm talking about.
Setup isn't that big a deal. With patience and a few special tools anybody can do one, although it's much better to have help the first time. And having the threaded carrier bearing adjustments is easier than messing with shims.