I gather that FLARM is much more popular outside of the USA. Are most well equipped sailplanes installing FLARM in the USA? What about other GA aircraft in the USA?

Is FLARM more common (or a necessity) at competitions in the USA? For club and casual cross-country soaring, it might be less prominent.

Having both FLARM in/out and ADS-B in/out is getting quite expensive. Would a budget minded sailplane in the USA get FLARM or ADS-B. Which has the most utility for situational awareness and safety in the USA?

What does FLARM offer that ADS-B does not? I'm assuming FLARM is faster and more accurate for gaggles. What's the relative refresh for FLARM and ADS-B data?

Yes, I know ADS-B out would open up some airspace that would normally be excluded, but I'm ignoring that factor for now.