Limabean,
This is my first post on this board. I have followed the Legacy dialogue with interest, being an owner of the Signiture III's. Some points I would like to add to the conversation:
Timeframe - I think it would be helpful if people would give a timeframe when mentioning their experiences with the Legacy product. Sean mentions Legacy 1's, which haven't been manufacutured in at least 8 years. Another poster mentioned that they weren't aware if the Classic and Signature brand name was still being used, which shows a lack of current information. Manufacturers of Hi End audio equipment normally are updating the materials used in their products periodically, so what is being used 5 years ago may not be in the current product. My Sig. III's are 1.5 years old, so my experience is fairly recent. My wife and I went to the Legacy factory in Springfield to audition the lineup. We heard the Classics and the Sig. III's. One look at the Focus and it was obvious that they were way to big for our room. The Signitures were clearly more open and relaxed than the Classics, which made our choice fairly easy.
Build quality - While at the factory we were given a tour of the facilities,and I had a chance to look at the materials used. The speaker cabling looks like the original Monster cable. Nothing special, but then nothing subpar about it either. I personally met the lady who does the crossover assemblies because I couldn't understand how the Classics and Signitures could have the same crossover frequencies but substantially different driver arrays. She took the time to show me the crossover of both the speakers so I could see the difference between the two units. I am not sure what the specifics are, but it was obvious that the Signitures crossover was tweaked differently than the Classics. The speaker are built by "people", not machines, so there is room for error, but all and all the manufacturing was very impressive.
Sound - I don't know why Legacy is know as a "boom and sizzle" speaker line. I have never had any problems with sizzling treble in my system. My speakers before the Signatures were Snell Type D's. I also audition Von Schw. VR 4.5's and Platinum Solo's. I am very familiar with my friend's Proac Response 3's, not to mention other speakers heard in various showrooms. I haven't heard anything to indicate that the treble in the Legacies are more prominent than the norm. In my system, they are, if anything, laid back and very unobtrusive. The bass can be problematic. The speakers reach very low in the bass. This takes careful positioning in the room to make sure that the sound is even. No more so than any other speaker that has a significant, true, low end.
Equipment - I don't think that you can expect "any" mass market receiver to have the backbone to drive Legacy's bigger speakers. The control over the multiple woofers is very important in getting the best out of these speakers. I tried Carver, McCormick and Muse before I settled on the Electrocompiniet (sp) 250 watt amplifier. I'm also using a VTL preamp, Pink Triangle/MSB and GyroDec SE/SMEIV.
I have listened to quite a few speakers since I purchased my speakers, but haven't run across any that I am willing to pay the "premium" for to get a better sound. They are not the best speakers in the world. Heck, they aren't even the best speakers in the Legacy lineup, the Whispers are. But for the money, and in my room with my equipment, they give a really nice sound. If you have a chance for an audition, try for the pair that fits your room the best. Sometimes bigger is not better. Hope this helps.