There is literally no way of answering that question for you. Drive them both and see which one you prefer. Personally I think that DSG is an absolute no brainer - all the involvement when you want it, and works like a traditional automatic in traffic. Plus it's quicker, and supposedly gives better fuel mileage (but I doubt there's much in it). There are some people who need the extra pedal and a manual shift to feel more involved though.
Mechatronics problems are not too common except on the very earliest cars and on a batch around MY08 (MY08 was subject to a recall). Either way make sure all gear changes are smooth and it accelerates smoothly in all gears. It's possible to repair Mechatronics units these days, but it'll set you back £250 for the refurbishment, nearly £200 for the fluid change afterwards, and labour for removal and reinstallation. Make sure the DSG has been serviced every 4 years/40k miles.
My DSG is on 97k now and has started to develop a fault which we think is a clutch pack failure, however these are very uncommon and I've just gotten unlucky it seems.