My Giga Studio 3 rig (4 PCs) is still functional for older projects still not finished, even though I've begun to move everything into one PC with Kontakt 5 and Komplete 9 Ultimate.
I'm still not convinced X3 can compete at 1.5ms with my old rig. Time will tell.
The GS3 setup is 1 PC (XP SP-2) running Sonar 4.0.2 as the main work station and 3 satellite (farm animals XP SP-2) that run Giga Studio 3 so I can split up my orchestra sections and have 64 x 3 midi tracks loaded with samples and ready to go. I use MidiOverLan and Forte Ensemble to talk to the 3 hosts.
Forte runs 2 instances East West Gold Orchestra, mainly just for orchestral percussion. I no longer use EW Gold for anything other than percussion.
GS3 libs. in use are Kirk Hunter Emerald, Advanced Orchestra, Some basic Vienna
Sam TrueStrike, EW Rare, Vienna Percussion Pro, Ethno World 3 Complete, and a bunch of other stuff.
Rendering the final is light pipe back into the workstation. All Echo Audio cards: 3 Layla 24, 1 Layla 3G, 3 Gina 24, 1 Gina 3G.
The big perk with this setup is absolutely consistent and flawless 1.5ms latency even with projects of 100 or more midi tracks and never a need to freeze anything.