The region is easy to reach (Basel airport is just 20+km away from Mulhouse..) and definitely one of the best training regions in Europe! Many pros live in the area, just across the border to Germany or Switzerland. You can ride for hours on dead flat roads in the Rhine river valley in winter or have climbs of all lentghs and difficulties in the Vosges with virtually no cars (big advantage compared to many roads in the Alps!
In spring, you can ride your bike in shorts in the valley and ski the same day on the slopes, where there is usually plenty of snow until March! Great food and nice landscape complete the picture! Definitely worth a ride!