I purchased a Wagon R In May 2009 and so far have been enjoying the ride in the wonder car. Its comfortable, spacious, looks good, relaible for long drives, fuel efficient.
Since my usage was ideally in the city, I preferred a petrol version and not a DUO. However, my friends who are using DUO also have a good feedback about the car.
I would only suggest you to buy the car from an autorised dealer and not a sub dealer. Though sub dealers give a better price then the authorised dealer, they do not really give a good customer service. I purchased the car from 4 Wheels in chembur and didnt quite enjoy the buying experience. I would recommend this product, worth its value..