As per P3asa, if you're happy with your car and won't get itchy feet prematurely for having the same car twice, i'd snap their hands off for that deal. Always worth asking for a little more though - they might even pay that deposit!
Get an extended test drive in the DSG as you're not coming from a DSG - it's not for everyone (I wouldn't have it as a free option). Can't think of anything worse than driving a car you wish you hadn't bought a month down the road.