The trick to expressive strings in Miroslav is velocity layers. Although not suitable for any kind of serious orchestration, for pop & rock strings it's adequate and a bargain at the current price. Velocity layering requires only a single MIDI channel. Yes, it does require loading multiple instruments - but any sampler does, and compared to, say, Kontakt, Miroslav is much lighter on RAM.
That said, the OP specifically asked for the "best" solo violin, and Miroslav ain't in the running. Spitfire's Albion
Solo Strings, however, are a contender for that title. At nearly 300 bucks, they won't be finding their way onto my hard drive anytime soon, but as soon as my lottery investments start paying off it's on my shopping list.