A couple of points just because a loudspeaker uses a particular material doesn't mean it is going to sound a particular way.
We had the Vivid line all aluminum drivers and they never sounded hollow at all. Same with the Kef Blades and the Kef Reference and R series.
There is a difference to what we would term hollow and being a bit forward. The Paradigm Prestige are a bit forward they are also incredibly exciting and visceral loudspeakers when driven correctly.
The hollowness that we hear with the Elacs is probably more due to cabinet construction then anything else, yes the cabinets are well braced but I don't think there is any stuffing inside the speakers, and that may be the culprit.
The Elac Adante will require an amplifier which is the inverse of the speaker, meaning slightly fat in the upper midrange and a tad rolled off in the upper treble.
The Kef R 300 sound fantastic and are less bright then the LS 50 because they have a lot more bass and are a true three way speaker.
We have never noticed any lack of coherency with the R 300 perhaps the stands were too tall.
We sell a lot more Kef R 500 which are just terrific due to the fact that the R 300 plus stands is approaching the more full range R 500.
In terms of Adante vs Legacy Calibres, no contest, the Legacy's are extraordinary, with unbelievable build quality, and every part is extremely expensive including the crossover components. Driver quality is off the charts. The Legacy is smoother, with better defined bass, and a glowing rich midrange. They are more like a $10k plus monitor in the league with the TAD ME 1 for half the price. They are that good!
The Adante is going to be a good speaker once people find out exactly the right components to use with it. The issue is going to be too many people are going to think sure it is an Andrew Jones design and therefore is will be killer and use the speaker with any old gear, this is not the case with Adante.
The Adante is a lot of speaker for the money, it will require a lot of time and investment in generally way better equipment then what is traditionally used in a $2,500.00 monitor.
Most likely a tube amplifier is what is going to work with Adante, or a very warm solid state amplifier and a laid back source.
We are still working with our demo pair and it has been busy lately so once we have had a bit more time with them we will report what combo is making magic with them.
An Arcam amp with the Class G amps are going to work well, Naim should also work, as well as Prima Luna and Rogue.
Dave and Troy
Audio Doctor NJ