Ive had both and id say go DSG for a couple reasons which have been said already.
For one, it's great if you just wanna relax and let the car do all the changes for you, if you feel like being more involved you can do that too on the paddles and via the stick.
Secondly, build some insurance into your purchase by ensuring they've kept to the service regime and for peace of mind I'd get it done again once you've bought one.
Lastly, you will almost certainly modify an ed30, buying a DSG saves you the expense of putting a new clutch in (like you'd have to with a manual if you map it) and the bonus farts they make on the down shift, especially with a sports exhaust, always put a smile on your face.