I have had a 3rd Gen, Airport Extreme (802.11draft, dual-band) since they came out, and I’ve been pretty happy with it. But, figuring that I had some eBay credit, and wanted 3×3 MIMO, I went on eBay and was able to pick up a 5th generation Airport Extreme for cheap. $60 later, I had one that was nearly brand new. And I didn’t want a current Airport Extreme because I think they look dumb, and don’t sit neatly above my Mac Mini. Oh, and nothing that does 802.11ac.
Apple makes it dead simple to upgrade (you can click on the current one in Airport Utility and tell it you want to upgrade. It downloads the current settings, and loads that config on the new one. The only real impact was my external IP changing, which isn’t a big deal. Total downtime, 60 seconds or so.
As for the base station itself, it does support native IPv6 routing, which is cool. Otherwise, it just feels faster. Using a device that only has 2×2 antennas (my Macbook Air), the speed difference is mainly due to signal strength, which is about 50% better than the 3rd gen. Using a device that has the 3×3 antennas, the speed is about 50% better (surprise!). But obviously, with my 50mbps Comcast connection, none of this really matters that much for internet connectivity (though torrenting seems better, as I’m guessing the router is able to track more connections). We’ll see if I get another boost when I swap the routing aspect of the network with the Asus RT-N16 I am working on.