My wife and I have rented Schwinns while on vacation for the past two years. They are indeed fine bikes. The frames appear well built, and all the components were very fine - totally on par for any aluminum bike in the same price range, actually probably better than average for any given entry bike price point since they aren't Trek, Specialized or Giant (actually, I've found Giant to be less price inflated than the others as well)

Not fancy, but very adequate for fun riding.