I own a pair of Helicon 800's and I am quite pleased with them. I had them originally paired with Sim Audio P3/W3 amps but have replaced the amps with some ARC gear lately. The Solid State amps just made some recordings sound to harsh on the top end. They also produced to "much" detail, if there is such a thing. Now everything sounds very natural and live like. Great extension on the top end, good bass and wonderful mids. All that combined with a realistic soundstage and good coherence. If you have the money for the 400's you might as well audition the 800's too. I guess it would also depend on the size of the room you are intending to use them in. My room is 36 by 18 and the 800's have no problem with that.
