Well, it is demanding. I admit to not using it much until I got a Gold license, as the Diamond was a bit of a bloated sluggish pig, not to put too fine a point on it. It does sound great, if pitchy. In fact, my main complaint with HS and LASS is the thing so many people are saying is great, which is the fact that they are pitchy. I say this in response: it doesn't sound more human because of that - it sounds more like you got the "B" players to do your session. As a side thought - maybe it's not a lack of tuning problems that make one's strings sound fake...
My general feeling about EW is that their libraries are ambitious, often very good-sounding, inspiring, and sometimes incompletely programmed or recorded. One needs to look no further than the QLSO to find, for example, curiously- and inconsistently-articulated attacks on the 6-Horn ensemble or three-trumpet ensemble, or abrupt cutoffs on releases in many of their titles, SD and SDII having notable examples. Admittedly, I have never attempted to record a giant library using a large number of musicians before, and perhaps it is beyond the scope of any reasonable-priced library to have all perfect performances without making the library a losing proposition money-wise - after all, look at what you get when you buy QLSO Platinum (or Gold, even.) - pretty impressive. It's still pretty great to be able to drop something in that sounds mostly there.
But what I can say is that VSL seems to suffer far less from tuning and articulation issues than any others - and also that I've had a great deal of success making VSL sound satisfyingly "Hollywood" with the right ambiences and positioning, maybe a hair of layering, and maybe the occasional bit of distortion (from Devil-Loc or the like) - whereas HS is HS, pretty much. If you get a lot of the VSL strings, you can get a lot of different sounds out of them. I'll never forget the first time I took something written with App strings and converted it to the Chamber stuff - the Chamber Strings are very agile and easy to direct. It made the App strings feel like I was driving a city bus by comparison. Not that they're bad at all! Just that when the sound of more players is involved... Anyway, it would be nice to have more, shall we say, florid playing options in VSL than are currently offered, but that often seems to come at the expense of malleability in programming. Though if anyone can make it work, maybe it'll be the folks from Vienna.