I don't have a P90, however, I do have a P89 and P97. In fact, I was shooting my P97 at the range today. I like them both and don't intend to get rid of either. Ruger is definitely a good gun at a good price.
Edited to add: In 2004, I paid $435 for my P97 NIB. However it did come with two mags. The P90 and P97 use the same magazines. They usually cost between $25 and $30 for 8rd. factory ones.