I don't think you can go wrong with either place. Why not do what arik suggests and spend part of your time at one and part at the other.
I skied one day in Saas Fee on September 16, 2007 and it was fantastic. You're skiing in a huge, high-altitude amphitheater that's just incredibly beautiful. Here are a couple of shots from that day.
Me at the top of the underground train you take. The summer-skiing terrain is directly behind me and the Allalinhorn (just over 4,000 meters) is the mountain rising behind my right shoulder:
This is the Allalinhorn from near the bottom of the skiing area:
And I love this one. This is a photo of my ski across a small crevasse right in the middle of the groomed run. This crevasse was quite deep, varied from a few inches to a couple of feet wide, and extending about two-thirds of the way across a main ski run. You would just ski right over it.
In America, the ski resort's legal people would have a cow if a potential hazard like this existed on a groomed run. In Switzerland, it's just part of the experience and I think everybody just understands that it wouldn't be a good idea to ski into the crevasse.
Here's the trip report I did on that day:http://forums.epicski.com/newreply.p...ote=1&p=918523
The year before, I skied for a day on September 19 on the Klein Matterhorn at Zermatt. It's very hard for me to really compare the two because the day I skied at Zermatt was just miserable. It was windy, foggy, and I had no idea where I was going. I was lucky enough to follow some boarders from the top of the summit cable car over to the ski runs, but they led me into the terrain park rather than the main piste.
: I managed to survive THAT little experience but still had a hard time really experiencing the terrain because the visibility was so poor.
Here are a couple of shots taken during the approximately 30 seconds that the sun peeked through the clouds. I have a feeling the place is incredibly beautiful if the sun is out but you sure couldn't prove it by me:
This one is looking sort of north (I think) from one of the t-bars. That icy hump in the background is out of bounds
This next was was taken looking back sort of west toward where unloading station for the tram you ride is located. You get off the tram somewhere to the right of that wall on the right side of this photo.
Here's the trip report I did for that day:http://forums.epicski.com/showthread.php?t=44190
As far as comparing the two, I think I would give the edge (slightly) to Saas Fee. That may be due entirely to the wonderful weather I had when I skied in SF versus the impenetrable fog I had in Zermatt. Both places are ridiculously beautiful. The town of Zermatt has more of a "scene", whereas Saas Fee is far more relaxed and laid back.
We stayed at the City Hotel
in Zermatt, which is owned by a Swiss mountain guide. It's a three-star hotel and what I would call "moderately" priced. It was very nice and our very comfortable, quite large room had a big deck with a fantastic view of the Matterhorn (when the sun was out
In Saas Fee, we stayed at the Hotel Eden
. This was also a lovely little family hotel and our room had a wonderful deck with a 180-degree view of the entire upper valley and peaks. There's a great little restaurant and bar right in the hotel. The downside, if any, was that the hotel is a little bit of a walk (maybe 500 meters?) from the base of the ski runs. This also meant that the hotel is in a very quiet part of the town.
Both towns are car-free, which you REALLY start to appreciate after a day or so (although you have to learn to be aware of the silent electric carts barreling down behind you). Both Zermatt and Saas Fee have an outstanding system of trails, lifts, restaurants, and huts for hiking or sightseeing. We did a Via Ferrata at Saas Fee that was really fun. We just really liked the atmosphere at Saas Fee.
I'd still do both if you can, though.