Jeremy, Looking back now, I think the Dimension Strings bundle is the best deal if you don't mind waiting a bit on the violas and basses. Here is my thinking:
1. You will get all the articulations you are ever likely to need (but see my footnote on trills).
2. To me, DS sounds as full as orchestral. It is a smaller section, but not noticeably so.
3. Since the strings are sampled individually, you can select how many players you want, so you can create a chamber groups.
4. You already have (and have mastered) Hollywood, so you don't need the cinematic orchestra.
5. You have the option of spreading the players in the stereo field, if you like. For example, if you are only using the 8 violins, you can position them in different positions.
With DS you will have solo players, chamber, and standard orchestra covered, as well as a good sized group for pop music.
BIG CAVEAT: You really need to buy the Vienna Pro Player—about $150, I think—to take advantage of DS fully. You cannot use all players in a single group with the free player. That sort of made me mad because I didn't know that until after the purchase, but buying DS early was a good deal and the Pro Player has a lot of excellent features. With the free player, to use all 8 players (or six in the case of cellos), you would have to have two instances and copy the MIDI.
I find the VSL matrix system extremely easy to use. (I stick to their standard matrices so I don't have to remember which keyswitch and controller does what, but you can create you own.)
Note on trills: The other VSL libraries, like Hollywood, have half and whole step trills. Dimension chose just to give you individual note samples that were created from trills. With the scripting that is built into their player, you can create half, whole, minor third, and major third trills. Good news: Lots of flexibility. Bad news: lots more work just to get a trill. I wish we had the recorded trills in addition to what is provided in DS, but this is no big deal—especially not for a string arranger and programmer like you.