I drove into Groningen, and the advantage of the location of the Hampshire is that it is kind of on the border between the urban center and the suburbs. Trust me, if you aren't comfortable with Euro-style traffic, you may not want to drive downtown Groningen; what with the narrowness and the bicycles and the roundabouts and all.
The Hampshire is easy to find once you know the trick, and that trick is to pay attention for its easy-to-miss driveway. Myself, I missed it twice and ended up asking for directions at a Buddhist temple just up the road (which is how I learned there is a very interesting Buddhist temple just up the road)
Once you're at the Hampshire, park the car and take the public transport or walk. There is a bus stop maybe half a km away, and the streets look fairly straightforward if you walk or take a bike downtown.
The other nice thing about the location is it is quick to get out of town and into the beautiful (even at the time of year I was there) countryside. I recommend a day trip to the coastal town of Pieterburen to visit the seal hospital there. Really interesting, and of course cute.
My room in the Hampshire was fairly large compared to what I'm used to in the Netherlands, with a decent bathroom.
Breakfast was very good, a nice choice of meats, cheese, cereal, fruit and breads that I found really energizing for a day of exploring Groningen.
I can't say its the best hotel in the city, but maybe because I've only had the pleasure of visiting Groningen once and this is the only one I've stayed in. Certainly I would expect more of the pricier inns in the city, but there is nothing lacking here.
The Hampshire is reasonably priced, well located (esp. for those traveling by car), and provides all of the requirements of a hotel in this class (tv, wireless, quiet location)
Two elevators, a large atrium and ample parking (and a wonderfully multilingual staff) seal the deal, and I fully recommend this hotel.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC