You know, to VSL's credit, I think they've bent over backwards to make their products the most intuitive and composer friendly products on the market. They've almost taken the MIDI out of MIDIstration. I remember five years ago when you had to have seperate tracks for seperate articulations. I was still using ROMplers at that time myself but I can only imagine what a bore it must have been setting up individual tracks for individual articulations. If I had to do that now... I probably would still be using those nasty ROMplers. I think a lot of people who use VSL products praise VSL for the stellar sound quality of their samples but forget about the enormous acomplishments they've achieved on the software side of the house.
Take the speed function for example, the software knows what sample to play based on how fast or slow you play. There is no keyswitching involved. If it's off a bit, then simply adjust the parameters of the speed matrix. Or, better yet, create your own speed matrix. Create multiple speed matrices and key switch back and forth between them.
Also, there is the velocity crossfade to switch back and forth between samples. Not to mention the ability to adjust the attack and release of samples in real time which is essential for realistic performances. Running out of RAM? Don't freeze, optomize.
The Vienna Ensemble software allows you to create your own presets which remain constant until you change them. If you keep all of your keyswitches the same for all of your projects then programming is just a formality and really not that time consuming. Granted there is a bit of a learning curve to some of this, which I am still learning myself, but it isn't nearly as steep the learning curve is for mastering the violin, trumpet, English horn etc. I can't speak for VEPRO or MIR since I don't own them but it doesn't take an astronaut to figure out the basic functionality of the VE/VI software. In fact, a monkey astronaut could pick this up pretty quickly.
Chris, my suggestion would be to start with a speed matrix (watch the video for speed controlled matrices). The SE doesn't come with pre-made speed matrices so you would have to create your own. Basically, a sustain patch would be on the low speed followed by a legato (mid to medium fast speed) and maybe a staccato for fast playing (depends on your taste). If it's a string instrument, create a vertical cell for portamentos that you crossfade with the legato patch. adjust the parameters to your liking; if the sustain patch plays when you want legato then move the slider to the left a bit. You may have to make some minor adjustments here and there to get the artics you want to play when you want.
I hope this helps Chris. I'll never go back to ROMplers again!