Yes. There are more high quality apps on Android than on WP. You will just have to give it time. Mango helps existing apps function a lot better, but to a degree, better programming will pick up the rest of the slack. There are some really slick/fast performing apps that I've tried, and others that are as slow as molasses. But in time, there will be more and more higher quality apps available that will perform just as well as Android ones - perhaps better due to more standardized hardware.
The quality of apps on Android have been superior to that of WP7 in my experience. A few examples are the official Facebook, YouTube, Angry Birds, and Fruit Ninja apps. They just perform a lot smoothly on Android.
The Facebook app on Windows Phone 7 is just downright horrendous. It's so laggy and slow that its painful to use. This is why I prefer to use the mobile site. Works better and has much more functionality than the official app itself and the People Hub.
The YouTube app also lags when scrolling and can be jerky. This isn't the case at all on Android.
Anrgy Birds and Fruit Ninja also run smoother on Android. Seems like the framerate on WP7 games are capped around 30fps while on Android they're like 60fps.
Uodates should fix all of these issues. The Facebook app for Android recently got an update and the app is just a pleasure to use now. Don't even have to use the mobile browser. Facebook needs to update the WP7 one because it just sucks.
I find the overall stock UI and apps on WP7 to be smooth but a lot of market apps are laggy and not consistent with the smoothness/transitions. Hopefully they get updated.
I just read that games on WP7 are capped at lower frame rates to preserve battery life. They still perform smoothly so that isn't a big issue.