I was never an owner at Orange Lake, so I can't compare the old system to the HI Club. However, we own a week at Sunset Resort on Marco Island, which was acquired by the HI club, and were offered the opportunity to join the HI club. Our unit originally just traded in the Registry Collection.
We never use our points to go to Orange Lake, so if that is what you want, I don't know how it would work out. We use all of our points in two ways: We exchange in RCI Points and convert points to the IHG rewards club (good for Holiday Inn, Candlewood Suites, Crowne Plaza, etc.). I was very angry at myself for getting suckered in to the original purchase at Marco Island, but the ability to use it through the HI club almost makes me feel ok about it.
A general observation is that the HI club properties require a LOT of points. But other RCI properties seem ok. The annual fee is not bad, nor are the exchange fees, in my opinion.
The HI vacation counselors do not seem very well trained; several times they have told us things that another one later denied, with the attitude of "oh, well, the other guy was just wrong". They are pleasant enough, though.
All in all, it has worked our fairly well for us.