Duff, the big problem with the Dash 400 is that is a speedy machine in the climb and cruise with an indicated speed of 280 kts possbile but in the descent there is a rediculous in built logic that causes Vmo to reduce gradually so that by FL80 (can't actually remember the exact level as is has been 2 years since I have flown one) it is back to 245 knots. This often used to mean on one of the 45 minute sectors that I operated if you took off immediately befor a 737 on the same route you could hold your own right up until the last part of the desent when it would go sailing past at 300 kts whilst I was forced back to 245 even if cleared at high speed. Apparently this is a design limitation for protection against bird strikes as the panel just above the main windscreen (i.e, at pilot head level) will allow a bird to penetrate right through at higher speeds.