I got the trial version of Laszlo before I tried Flex. I was very impressed - it has a good, rich look to it. When I talked with the Laszlo folks, they were touting the fact that while they do produce Flash SWF output now, they would offer, at some point in the future, other possibilities. So they claim they won't be tied forever to Flash.
I can't speak to pricing, but my management was leery of them because the company is so young (we are a big fortune 500 company) and was worried what would happen if they went under. My feeling is that they will go under if fortune 500 companies don't buy their product! Anyway, I then tried Flex. I love Flex. I feel that the object model is much more complete than the Laszlo product. There are a ton of helper classes in Flex, from UI components to data validation to data formatting. It is very easy to connect a Flex application to web services, HTTP services, and J2EE beans. You can also use other Macromedia products, like Flash Communication Server, very easily. The one issue I really had with Laszlo that it was difficult to use 3rd party Flash components with their product. We use a 3rd party charting package and it just won't work with Laszlo - you are tied to use their products. That's my 2 cents.
