I haven't been paying much attention to EW lately so maybe things have changed but what I've never been able to understand about EW is why they insist upon recording samples with their own built in ambience. Even the close mic position has too much ambience.
I'd say that's true of EWQLSO, but have you heard the close mics of HS? Between those two libraries, the amount of ambience definitely has changed - even the farthest mics of HS are vastly drier than the old orchestral library.
I definitely like the sound of HS, and I don't think I've heard a demo of VSL strings that sounded anywhere close to that sound to me (feel free to link some). But the PLAY plugin isn't nearly as good as either the Vienna player or Kontakt, and HS seems to have many programming issues even after being released for a year. Not to mention that the user features and customizability don't come anywhere close to the other two plugins. If the programming quality was as good as the recordings, it would be hard for any other string library to compete, but I know of a number of people who own the library but use it very little if at all.
LASS is limited on articulations but it has what I need most and I've been extremely happy with the sound and realism I've been able to get out of it. It's also very light on resources (even when using all the divisi) and I find it extremely quick and easy to use. I just play it and get results I'm happy with without much fussing between a million different articulations and variations. And they totally nailed the legatos.
But at this point I'd say the 300 pound gorilla isn't HS but the upcoming CineBrass. The sound so far seems to be phenomenal and the programming is as advanced and user friendly as anything I've seen. It's nice to see vienna trying new things like Dimension Brass but so far the reaction outside of the Vienna diehards has been fairly lukewarm, particularly to the sound quality.