DG,
I agree that the volume level of the legato transitions is too loud and uniform when played straight, however this is a minor problem that can be fixed (and obviously will be) in programming at some point. The VSL programming has been absolutely incredible on all their completed libraries (especially with all the wonderful new elements and tweaks in VI) and this is an early release. Not to lecture you (of all people) but aren't we getting a little spoiled by the near-perfection offered here regularly? And we demand it even in "Beta" products like this.
One thing I tried was to layer the sustaining "Uu" with the legato of "Ah" (or the reverse) and it sounds almost perfect. Of course, it is two vowels simultaneously, but first of all you can't enuniciate words yet ( I mean the sopranos, DG, not you personally - I assume you can speak the Queen's English quite delightfully), and also singers - especially choral - are so imprecise with their enunciation anyway that half the time a "Uu" IS an"Ah." And on top of that, ALL vowels are the same when you get up in the higher register.