Late in the 2008/2009 season, it was time for me to hit a mountain not far from where I once lived for over 20 years. For quite some time, the formerly independent resorts have been linked with each other so that you can easily ski at all of them in one day. Sure, you may not get to all of the runs, but you will get a nice overview.
Most of the runs are exposed to the sun, and this might be an issue whenever the weather is not very cold. In April this will force you to be on the safe side and hit the steep, off-piste stuff early. By 1 P.M. it was already time for me to stay away from any challenging areas, but that was long enough to be sure that there is a lot of good off-piste skiing. Quite a lot of it is short, but there are a few longer runs. In mid-winter you can ski from the top to the valley area, and this will keep you happy and busy for quite some time.
Overall, my brother and I liked the Fiescheralp area best in terms of terrain, but the downside was the tram you have to take to get to the top. Even in April we had to wait over 20 minutes just to get onto it. In mid-winter, this might become a very big issue. According to my brother, this area will close when the avalanche risk is too high.
If you spend some time in Valais and intend to ski at several different resorts, there are many places to stay that are not expensive resort accommodations, although some smaller resorts do offer affordable weekly rates; some are even ski in/ski out. If you need an apartment for up to 8 people, let me know; my parents and brother own one.
Yes but limited
Other Resorts in Switzerland