I did a transplant from DWC to Dutch Bucket this year... I did nothing other than move the net potted plant and turned on the new system, no adverse effects at all.
As Matt says, keeping the temp in the reservoir low is key for an outdoor set-up, as high temp = low oxygen levels in the nute solution. We get 30-40C days here, so I needed two air pumps running 4 stones to get a good level of 02.
Also, try and make sure the bottom of the bucket drains well, you don't want very much water ponding in the bottom of the bucket or you will increase your chances of fungal issues.
For next season, I'm modifying my set-up to have the return valve draining vertically from the base of the buckets (rather than at the base of the side of the buckets), as I had a 3/4 inch of nutes ponding in the base of my buckets, which I think contributed to a bit of black spot.