Forgive the double post but I have now purchased and upgraded an Adder
Very happy with it. Nice step up from a sidewinder and it has more teeth than a hauler. 2 small hardpoints and 1 medium one mean it's a small trader you probably want to think twice about taking on. I've upgraded the drives, thruster, power and distribution and it handles pretty well, pretty close to the Sidewinder in fact (that's with the upgrades) Off the top of my head I've upgraded the cargo space to 12 tonnes so slightly less than the hauler. I think I paid about 87,000 credits for the base model.
The only thing is it looks feck all like the original Adder and more like the Hauler's nastier brother. It has a distinctive shuttle like shape and the cockpit visibility isn't the best. Oh and for some reason the steering wheel is on the wrong side
Overall nice little ship for small trading that can handle itself in a scrap.