If you set up a very simple custom matrix which has legato for the first cell, sustain for the second, detache then staccato for 3rd and 4th, you will be able to use almost all of the normal string bowing articulations by keyswitching between just those four. You can play a huge amount of string music beautifully with just those four articulations. If you start with sustain, you will get a fresh downbow, which can then be switched to legato for a new smooth line. If you need shorter articulations, more pronounced and shorter, you then can use the detache or staccato.
One thing that will always make your line sound more natural is to mix articulations, based on the phrasing of the line you are doing. So if it has a feel of starting on a certain note, even in the middle of a phrase, use sustain, detache (if the note is short enough) or even sforzando, then immediately switch to legato to connect the rest of the line or phrase.
The portato articulations are really good also, and in strings may be used instead of detache to get more complexity or a slightly different attack to the note. Also, the legato repeition notes in the strings - those are really good if you have a slower line, that you want to sound more natural.
The great thing about the VSL legato is that you can connect any previous note to a legato transition and target note. That is an awesome feature, when you think how it allows any kind of attack or dynamic to be used with a legato transition note. So if you start with a forte piano, then go to piano legato, you will have a totally different line that has an accented start then a soft legato melody. The same thing applies to the dynamic samples, which if you match correctly (simply by listening) you can create transitions to any following legato note. That allows for example, a crescendo sustain to a slurred fortissimo jump. Something you might often want to use for dramatic effect.
