Manually - with my fingers on a weighted piano keyboard / Midi Controller - Arturia Keylab 88.
The same way I play in any midi data so my comparison is based on playing other virtual instruments the same way.
For Spitfire Symphony Orchestra I have the 16 drum pads on the KL-88, assigned to midi notes, to do the key switching which is out of range,
below the lowest note of an 88 midi controller. There's an other check mark in the Con column for Spitfire.
I'm comparing to Native Instruments Stradivari Violin (my go to solo violin) or any of the instruments in the Cremona Quartet.
Also Session Strings Pro II - and the Vienna Strings in the Kontakt factory library
(i.e. once I modded the nki to have volume swell on the mod wheel)
also Symphony Essentials stings. Symphony Essentials needed some under the wrench fine tuning also.
These are the relatively newer of my strings libs.
My older go-to for full string sections in Kirk Hunter Diamond. Somewhat tedious key switching but a lot of flexibility inside of each articulation,
and perfect playability if riding the CC11 fader on the controller.
However the Diamond solo violin is far inferior to the NI Stradivari Violin.
I'll still use SSO strings for the sound in some instances but SSO most always needs some tweaking.
I'm patiently waiting for the release of Aaron Venture Infinite Strings
because his Infinite WWinds and Infinite Brass are the most playable instruments I've ever owned.
Exceptional - perfect actually.
No key switching needed. Anything you can imagine can be played with fingers and mod wheel only.
Even trills and rips. Very good legato programming also.