Bryan,
4 reasons I picked LASS over Hollywood Strings:
1-Sound
To my ears, LASS sounds more like real strings, especially in an exposed setting. HS sounds gorgeous (especially as demoed by Thomas Bergersen...but of course that's not exactly fair considering he's not only one of the developers but possibly the best "orchestral mock-up artist" there is), but LASS sounds more like real strings to me, as opposed to a high end sample library. If you listen to Andrew play his little live solo line demos on the LASS website I think you'll hear what I'm talking about. A very realistic sound right out of the box.
I'm not sure if this is due to the true divisi recording or the amount of scripting, but it's what I'm hearing...and of course that
is subjective...
2-Flexibility
As Steve pointed out, HS doesn't have true divisi recording, they just miked different parts of the sections separately to emphasize the sound of the players closest to the mics, but everybody is still playing. While this should be fine for divisi writing within a score, it really doesn't give you the flexibility to "scale your string section" to whatever size you may require. I write in a lot of different styles and there is no telling what I may be called on to do next. Whether I need a studio size section a la Coldplay's Viva La Vida, a chamber ensemble, a combo for dramedy or a period schmaltzy TV theme, or full-on soaring orchestral strings, LASS delivers on all counts.
And of course there is layering too...I've had great results layering LASS with the S mic strings from EW Platinum for example, you get that big hall sound from Benaroya with the articulate nature and bite of LASS. And of course you can layer smaller sections with much more flexibility.
Everybody loves doing the "Big Hollywood Sound", and I certainly do some of it, but because everybody loves doing it it's a really crowded field. There are few guys that could live off that stuff exclusively...so for me as a working composer, flexibility is paramount. Maybe the two products are quite appropriately named, actually...
3-Platform
Let's be honest, Kontakt is a far more advanced platform than PLAY. It's not just that it's more stable and gentler on computer resources, it's also that it's way ahead in the scripting department which ultimately makes libraries more playable, more like instruments, and less like an "articulation assembly line".
Now hopefully PLAY 3 will be a big step forward but the truth is EW has a lot of ground to make up. Especially since the numerous developers on the Kontakt platform keep pushing each other to new heights.
The Auto arranger script in LASS is pretty incredible, and so are the scripts from Samplemodeling or Orange Tree's guitar libraries, to mention just a few. PLAY is really nowhere near that currently.
4-Company
I certainly have nothing against EW, I own tons of their products and the original Gold/XP orchestral library is definitely in my top three bang for the buck libraries as far as what I made from it in upfront money and royalties when compared to the purchase price. It may even be number one, as a matter of fact.
However, generally speaking EW's philosophy is to spend a lot of time and money making great libraries (and they are great), but when they are released, that's pretty much it. Sure, if there are bugs they will fix them, but then it's on to the next thing. That's probably the only way to go if you have as big of a product line as EW does.
By contrast, Audiobro (really though, what kind of name is that...

) only has one product, LASS, and it's quite clear that it is a labor of love for Andrew. The amount of development this library has seen since its release is staggering, and most of it has been free to the registered user. The just released sordini addition is the first thing they are charging for AFAIK. It's really more of a "living library" than a finished WYSIWYG product.
And the stuff they are still planning, such as convolution presets to emulate the string sound of famous recordings, made it clear to me that I wanted to be a part of this product and company.
I'm not saying I would never buy HS, there certainly is a possibility I might get it in the future, but for the reasons above LASS was my first choice in a high end string library, and the more I use it the happier I am with my decision.
HTH,
matto