zermatt is decent but as mentioned, saas fee is closeby and it has a better park ....
+there are also a lot of summercamps and infrastructure(tramps and other leisure activities) at saas fee while zermatt is a bit lacking in that department ...(saas fee also has a really cool via ferrata)
but... in zermatt you're at the foot of the matterhorn, quite possibly the most beautiful mountain of europe and you can do really cool glacier walks from zermatt, for example you can walk up to the schonbiel hut at the foot of the matterhorn and spend a night there, it's really pretty cool !
so if you're a parkrat and strictly going for park/freestyle, i'd advice to go to saas fee
if you're more of an alpine adventurer, go visit zermatt and experience the alps for what they really are! :)