I can only confirm what John Eacott says regarding the
A109S. Forget the 109E - too weight limited. The S is very quick, and even at VNE is smooth. Plan your flights at 155kts TAS. It's very easy to exceed VNE in the cruise if you aren't paying attention - there is even an aural warning ("airspeed") as you slip through 168 knots. Excellent autopilot, SPIFR certified, and CAT A up to MAUW under normal conditions. Cockpit is definitely cramped though. Not good for bush landings as the main wheels are quite small and the belly is close to the ground. Good range when fitted with both aux tanks - around 3 hours @ 150 kts from memory. Seats 8 in normal configuration. Empty weight is around 2100 kg, full fuel is around 640kg(??), and MAUW for take off is 3175kg.
Aux tanks do not affect cabin or baggage space.

Cyclone,

In the A109E/S the extended range tanks fit under the rear (forward facing) seats and don't reduce either cabin or baggage space. Only difference is that you have to think more about CofG when it comes to loading the beast.

HP

Cyclone, Check your pms.