I'd have to agree with both eckhard and c680_pilot but with the caveat that whilst c680_pilot is right that both aircraft have the same max speed limitation, the CJ3 will achieve it in the cruise more readily than a 2+ as it has more excess thrust available and thus is faster on a specific route (albeit only very slightly).
The CJ3 gives more room for the passengers, more baggage capacity and a greater range. As an example, I have flown a CJ3 from the UK to Lebanon direct, with 2 passengers more than once and to do that with a CJ2+ would need a fuel stop to be factored in.
All depends what the client wants though and for most short flights around Europe a 2+ would probably be fine whilst a 3 might get you some longer trips.