@HSM1
I think VSL has one of the best legatos out there. The "problem" is only to set up a matrix which is very time-consuming. But I like and appreciate it, and for me it has so many advantages compared to other libraries. When you buy a non-VSL library, you have a fixed articulation mapping.
I do not own any other library (apart from Composer Cloud X), but I watched many review videos only to understand how articulations in other libraries are mapped. In VI (Pro) you can do everything, you can set up your own behaviours via crossfading, speed or velocity. Endless possibilites, this is far superior to everything else in my opinion.
Orchestral Strings has, in fact, nearly all the articulations you mentioned in your post. You can "copy" each (!) while combining patches. And the best thing is probably the performance trills, so you do not need to switch to a trill articulation. I miss that in other libraries, some have very bad fast legatos as well.
I hope there will be a kind of performance trills in the Synchron Series.