I've heard them, but not extensively nor with Smaart. The upper bass range has decent rear rejection, the deep bass doesn't. It's a bit less "tight" sounding than the US and TS221 models.
Pure sound quality - I like the TS221 the best of all the Fulcrum subs. The CS121 is a good option if rejection is needed but budget doesn't allow for an array of -221's. Smaller rooms that need a flown sub and less gak bouncing around the ceiling seems like the best application.