Are you a diehard OT fan? Are you unsure, or skeptical? Let us know!
Neither nor. My experience with Orchestral Tools' libraries has been an unfulfilling one. I generally do like the sound and the quality of their recordings. I think they are between very good and outstanding. However, their libraries often have so many inconsistencies that I can't use them professionally.
I own Berlin Strings, First Chairs, and Symphonic Strings. Out of the three, First Chairs has the most gorgeous recordings, and also the most outrageous inconsistencies. The pizzicati of the first violin, for example, are several db quieter than the ones of Vl 2. What is called 'staccato' in the viola would classify as a portato in the second violins. Just a very simple line, staccato patches, BST First Chairs v2 (the Kontakt version) out of the box - Vl 1, Vl 2, Vla, Vlc, Kb:
app.box.com
Try mocking up a staccato passage with these patches. It should be a simple excercise really. But with Berlin Strings First Chairs, instead of recording the passage and cleaning it up, you now have to start fiddling with volume automation, try to abuse the time stretch feature in Kontakt to create a crisper version of the viola articulation, adjust mic settings. And on and on. It's just a huge workflow- and time-killer. Much as I like the sound, when working on a deadline, it's simply not possible to use these samples for me.
Another example is the niente switch in First Chairs Kontakt. It is there, but it doesn't work. Toggle it on or off, it makes no difference. I wrote to support about it. They acknowledged the bug, and wrote that they'll look into it. One year later, there was a huge update, the BST v2 update. The niente switch still doesn't work. I wrote to support again. Now they told me that solo strings can not play to niente anyway, and that they would not bother fixing it. So there is a nice little switch on the interface that does nothing, and OT can't be bothered to fix or remove it.
Berlin Strings is a bit better in that regard. But still, it has enough inconsistencies and inconveniences that I rarely use it. Berlin Symphonic Strings is pretty good and works decently well for me.
The Sine player, unfortunately, hasn't improved the workflow deficits for me. Quite the opposite. There are polymaps, which is a really good idea. But you can not lock them. So you can spend an hour setting up a polymap. Press the wrong keyswitch, and it is gone. Irretrievably. To make things worse, keyswitches don't always trigger correctly for Sine on my system. So even if I press the right keyswitch, the polymap might be gone. This makes the feature basically useless for me.
Overall I can say that I really like the sound and recording quality of the samples. But huge workflow pains make the libraries slow and tedious to use for me. At the price point Orchestral Tools are asking - and especially with their no demos, no refunds, no resales policy - it has made OT a company that I avoid. When working on a deadline, I need libraries that are much more consistent. Also, with the price point and sales policies, I expect a lot more and much faster bug fixing.