Thanks for the responses and suggestions.
I wonder whether anybody is reading this who uses EastWest or Vienna Symphonic Library or similar for big, MIDI-intensive projects and can say, "CbB handles those types of projects well," or "It's a tough slog" or can otherwise share their experience?
Since it came up, here's my system info:
Motherboard: ADK- Intel LGA1151: Micro ATX Z170 2x 16X PCIe, 1x PCIe 1x, Up to 64 gigs DDR4 2666+, M.2, USB3.1/C, USB3.0, Sata 6Gbs
Processor: Intel Core i7 6700 Skylake 4GHz Quad 8 meg cache with HT
RAM: 16 Gigs (2x 8 Gigs) DDR4 2666
Operating System: Microsoft Windows Home 10 64 Bit OEM
Hard Drive: Seagate Caviar 500G 16Meg Sata 600
Hard Drive: Seagate 3TB Sata 600 7200 RPM 64meg cache
Focusrite Scarlet 18i8
Cheers,
Jonathan