My template is just a whole load of Instruments, complete with all the controllers, that I like to use when programming for orchestra. You can use the Presets for the Instruments which come with VSL, but I don't think i use any of them, because I have a much more efficient way of working that these don't cover. Also they don't include all the articulations that I like to use. However, once you've built up your own library of Presets, loaded them into a few instances of VEP you can save this whole thing as one file, and then you only have to make a couple of clicks to load all these samples. I have a Nuendo template that automatically connects all of the channels that I have in the VEP template, so although the loading time for the samples at the start of the day is significant, I only do it once, no matter how many projects I have to open and close during the day.
Nothing is loaded into RAM during playback. However, if you are streaming a huge number of instruments at the same time, you might find it better to stream the samples from 2 discs rather than 1. This is what I'm doing, and I have no problems with streaming.
DG