The a/c restriction is actually 240kts to 8000' but reducing slowly from 10000 ie around 270kts restriction at 9000'.
The reason for this is the windscreen.
If you try and fly faster you get an extremely annoying female voice shouting "HIGH SPEED, HIGH SPEED".
I hope this helps. If you are a controller, try and help erj pilots by keeping them above 10000' as long as possible and give them early climb to 10000 if you want them out the way quicker.