As of patch 2.25 Extreme Primals on my server through the Party Finder are basically dead. Pre2.2, we had a ton of groups attempting these on an hourly basis and now they are few and far between. Hell, successful groups are even rarer these days.

I point to the fact that the rewards are no longer relevant. Even with the new "Primal Ponies" these trials are no longer interesting to the vast majority of players who have defeated them in the past. I have a proposed solution for this...

Give us the ability to turn in Rowen's Tokens for 25 Soldiery each. A weekly quest that gives 75 Soldiery would encourage players who are capable of completing these fights the incentive to go back and do them again. Those of us that wish to try and get a shot at those nice new mounts need people to want to do these fights.