Floating floors are a relatively new phenomena for wood floors. Usually, the top 1/3rd layer is a hardwood veneer, or plastic veneer, the next layer may be an MDF type of board, and the last 1/3rd is possibly cork. This type of flooring is not as expensive to install as is a traditional hardwood floor. You can't refinish the floor if it gets worn, nor is it easy to replace a 'bad board'. In fact, you not even be able to replace any bad boards. A true, 3/4" hardwood floor can be refinished up to 3 x's (in most cases), and boards can be easily replaced. The floating floor is only attached at the 'seams'. It's NOT nailed to the floor. The floor is 'held down' by the trim along the edges. It's designed to move.
The buckeling isn't good. The creaking can be a number of things, of which may be due to poor installation or 'character' of the floor. Personally, I am partial to a true hardwood floor. To me, the floating floors sound hollow especially over basements or crawlspaces or the like. Plus, you can't refinish or repair them. If you want to 'test' the developer's knowledge against yours, first, go to a Home Center or any Flooring Retailer and tell them you're interested in a floating system and want to know how it works. Then, ask your SAME questions to the developer. Read Pergo Vs. The World for starters to read about the different types of hardwood flooring. (I like the article. It's accurate.) And if you get conflicting info from your developer, decide if whatever else they're telling you is 'true'.