Hi Mike, for orchestral brass, I rate the Roland SRX 10 best so far. It has a C-trumpet section that sounds 100% real. The trombones are realistic, too, only a bit low-volume and soft, which you can compensate by leveling the other sounds. The French horns are very realistic, too, as are the beautiful muted trumpet and trombone sections.
Official demo:
https://soundcloud.com/rolandcom/srx-10-...-brass-ensemble

In my opinion, some of the Korg M3 brass expansion sounds were equally realistic, the French horns even a bit more dynamic. (However, there were a few so-so trumpet sections in it, too, the bigband sections were not so good).
https://soundcloud.com/korg/s008-f-horn-heroics-ex1?in=korg/sets/m3-xpanded-demos
Garritan has a very good classical solo trumpet (recently praised by a pro trumpet player in my Youtube videos) and some good sections, but I didn't like them as much as the SRX10.
IMO some of the preset Yamaha Motif XS/XF/MoXF brass sections are really good, too (e.g. medium brass section), but in the direct comparison they can't beat the SRX10 C-trumpets.
So, for brass maybe:
1. Roland SRX 10
2. Korg M3 brass expansion (Kronos will be at least as good)
3. Garritan GPO Lite / Yamaha Motif XF presets

For classical woodwinds (Clarinet, Oboe, Flute, English Horn), I like the Garritan woodwinds a lot, but I was even more fascinated by the Korg M3 woodwinds expansion. I rate the Motif preset woodwinds quite good, but not top. The Integra SuperNatural woodwinds are very good except if you use vibrato, which is again not sampled, but artificially created. The Integra's PCM woodwinds (especially SRX06) are good, but their age and limited wave data doesn't allow real highlights.
So in summary for woodwinds (except sax):
1. Korg M3 woodwind expansion
2. Garritan GPO Lite
3. Integra SN-A woodwinds + SRX06 woodwinds combined
4. Yamaha Motif XF/MoXF

Regarding choirs, I don't use them much in the MoXF, and I am very happy with the excellent, even if old, choirs of the Roland SRX06, and also the SuperNatural choirs of the Integra.

Everything subjective of course! Hope it helps.