I have bought Spitfire Symphonic Orchestra. And compared it to previously rendered track. See : http://www.sinerj.org/~loyer/GeneralMIDI (at the end).
For 49€, it is very impressive.
I had to load one instance per track (while Kontakt or EWQL can load all instruments in a single instance) but it works well.
No timpani are played under C3… and my track has some lower notes. (According to Wikipedia, Timpani notes can be quite low : C2).
I don’t know if there is a way to store in the DAW project the articulations. If not, we may have to create one track per articulation ! Other orchestra suite propose some keys to switch between them, this prevent multiple tracks. (However, here, with a plain GM file, there are no specified articulations).