In terms of sonic quality, Montage is a Winner, the hardware D/A A/D converters is huuuge and sounds well, stunning, like nothing else your hear before. Period.
In terms of flexibility, I'm with you...the VST can do more and more and more, but if you played around with u-he Zebra 2, Montage is the Big Brother of Zebra's Synths, modulations all over the place and that unique Analog Sound, I had all the Yamaha keyboards since the first Awn + FM , through the EX5, vl, fdsr, etc, and I never heard a Keyboard sounding soooo good as the new Montage 6 !. I will go again today to the Namm 2016 and I will get some tech info to write it here tomorrow, excellent synth ! (sorry my english is not so good, apologized)

I think you will have to hear it for yourself. I agree with Axel, whom I don't know, but was obviously at the recent NAMM show in Anaheim. It truly is unlike any hardware synth you've ever played. We'll let you do all the comparisons yourself. Contact your local music store - make sure they are the list of retailers who signed up to carry the Montage (due out this spring)!