I owned a pair of the Sierra 1s about 15 years ago in piano black which were being driven by conrad-johnson amp (ss) and pre (tube). The only reason they were sold was due to my own economic factors at the time. Nonetheless, they were extremely well constructed, especially the cabinet - quality was impressive at their price point. They were an easier, and perhaps more forgiving speaker with its SEAS tweeter. Bass response was impressive with better than expected mid-bass (“punch”). Seemed like quite a bit of thought, design, and effort went behind this speaker as it really put Ascend Acoustics on the map.
To be honest, I’ve been debating on picking up another pair for my office system. Definitely one of the few speakers I regret selling, but unsure what its competitors are these days. I really can’t see going wrong between either Fritz or Ascend.