Adam
I have flown a 690B. It had Dash engines and performed like a ballistic missile which would outclimb many light jets.
Speed was 290 kts, 100 kts over the fence! Bags of character with quite a cosy cockpit.
An ergonomic nightmare
Down side wirh the Dash engines was the engine and prop noise was like a hammer drill. Pilots seats were better Pax areas would give you a headache.
The one I flew had a nasty wingdrop in the stall but that may have been unique to that particular aircraft.
Having said all that loved it as many do for its looks, quirkiness, speed and climb rate as well as its strong build.
Pace