having gone to the trouble of finding a training company that use artics to do my class 1 i now have an interview with a company that uses wagon and drags… whats the difference driving wise between the two, i imagine the drag will be easier to reverse but will need more room at junctions etc am i wrong
Drag will follow you better than a artic, let cut in on corners etc. No headboard swing as with and artic. As for reversing mmmm the bigger the drag the easier tri axle easier than tandem etc oh and A frame never had the pleasure but they apparently take time and skill to reverse! LOL When you can reverse an A frame your a lorry driver! 
Overall id say they are easier to reverse, one down side is turning circle, with an artic you can be a tad rough when empty and screw it round in a tight area, with a drag thats a no no they need a area the size of Kent to turn round. Generally you can go forwards into tighter areas than you can with an artic. Thats kind of dependant on the size of the drag combination though.
A 6wheeler with a tri on is a whole lot bigger than a four wheeler with a tandem on.
In my opinion you have done things the right way round.
Learned on an Artic and gone to work on a W&D
If you can manage an asrtic you will pick up the drag quickly enough. It is harder if you learned with the drag and then went on to Artic.
The only thing I have to add about W&D is to try to keep them straight if you can. Bend them as little as possible when reversing. They dont take a lot to get them round so I find it makes them easier to handle