Keep in mind, this is strictly just my opinion, I know alot of people that love PGA and think it's the greatest. But after having gone to over 45 different parks around the world, I know better. I'm a diehard park enthusiast, I love parks for all the different types of experiences a park has to offer, not just the coasters.
A great example is BGW. On my very first visit, they only had 2 coasters, Nessie and BBW, and the park immediately jumped into my #1 favorite park spot. The place is absolutely brilliant, the theming, the setting, the ride selection, the food, quality coasters, the atmosphere, everything, just a complete awesome all around park. Another example is Holiday World, only Raven was there on my first visit, had an amazing time. So in my book, a park doesn't need 10 coasters to be the better park.
PGA may have more coasters than SFMW for now, but like BGW, it's the theming, the atmosphere, selection of quality rides and attractions, etc. that makes SFMW the better park in my book. PGA has more coaster(most of them lame)and that's it. They have absolutely nothing else to offer, except a stripped down carnival atmosphere and long lines, thanks to Paramounts destruction of a once beautiful theme park and disregard for capacity.
Oh, and BTW, SFMW has 5 coasters. Don't forget about Cobra, a very fun family coaster that, unlike PGA's family coasters, you don't need a kid with you to be able to ride. Give SFMW 5 more years to build up their ride count, and mark my word, it WILL be regarded as one of the best and most beautiful theme parks in the US.