Acratech is an AWESOME company!
Scott, the owner/founder is a real stand-up guy, and the products they make/innovate are truly outstanding(as you've stated ) and IMO, are the *BEST* on the market.
Really Right Stuff makes very good stuff too. However, to ME, the "open ball" design that Acratech employs is simply the best, most straightforward design allowing the easiest/lowest amount of maintenance(or lack of potential repairs).
Their products are very well priced, extremely well made, and yeah: super lightweight for the weight they can support!
I've seen their facility in-person(as I'm local to their shop). They're a small company, but that's a good thing IMO. They don't outsource any manufacturing of their products/parts, so q/c is extremely tight and controlled to the nth degree.
If anyone reading this is looking to buy the last ballhead they'll need for the rest of eternity, give Acratech your business !