The Corsair Obsidian 700D and 800D are top-end products; Corsair's design team hit virtually every target one could set for a full-tower ATX enclosure. The 800D is designed for the enthusiast that wants a top-end case with all the bells and whistles and wants to show it off afterwards. If you want to do something special with case modding, or if you have a need for hot-swap hard drives, than the 800D is a great design. If, on the other hand, your mainly concerned with hardware, but don't care for the window and don't need the hot-swappable bays, the 700D is the better choice. It should go without saying that both cases are effectively future proof--there's no chance of the ATX spec evolving to a size that these chassis couldn't accommodate, and Corsair has already provided space for power supplies larger than even the 1200W units on the market today.
The one caveat to keep in mind when considering the 700D and 800D is that you don't need to spend this much money to buy an excellent enthusiast chassis. In this case (pun intended), the question of whether or not either chassis is worth its purchase price depends entirely on what you want to do with it. If you're a fan of Batcave Chic or you fall into one of the categories mentioned above, then it's a no-brainer. If you don't, there are other options that are more budget friendly. Alternatively, you may want to wait for Corsair's 600T, a mid-tower version of the 700D with LAN party-friendly changes and a price tag of just $149. We don't have an exact launch date on the 600T yet but Corsair expects it will arrive in time for the back-to-school season.