Having started with Spatial's early and best platform, the M1, and then each upgrade (compression tweeter x 2 + x-over upgrade) and now owning the Sapphire M3's, it's clear to me that the Sapphires are in another league entirely from SA's earlier M products. The missing detail from the early compression horn tweeters is cured by the new M100 tweet. The weak and absent base from the earlier versions is no longer an issue. SA's newest effort is simply a wholly different product than the early platforms. Finally, the new speaks allow the use of tubes amps without as great a penalty. Yet, despite the "failings" of the early platform, the speakers' presentation of the midrange, especially, horns, was remarkable.