Are there any differences between the 802.11n final and draft specifications?
Solution 1:
The Wi-Fi Alliance added some important compatibility tests between their "draft N" and their "final N" certification programs. I recommend buying devices that have received official "final N" certification from the Wi-Fi Alliance. There's no good reason for things that are still on the market today to not have final-N certification. Companies that are still selling draft-N stuff and haven't gotten it re-certified as final-N either can't, because their stuff doesn't measure up, or they won't because they don't care much about updating this after they ship (good luck getting bug fixes out of them).
But that said, a bigger thing to look for as you're buying a router in mid-2014 is to get something that has dual-band concurrent 3x3. Being able to use both bands at the same time is a huge flexibility and performance win, and modern 3x3 radios can support data rates up to 450mbps, whereas the older (but still more common) 2x2 radios can only go up to 300mbps.
You want to see a Wi-Fi certificate that looks something like this.
Update 2014: Since mid-2013, you should be looking for dual-band concurrent 3x3 802.11ac (well, it'll be 3x3 N in 2.4GHz (216Mbps when using just 20MHz-wide channels to be a good neighbor for other networks and leave room for Wi-Fi) , but 3x3 AC (1300Mbps) in 5GHz)
You want to see a Wi-Fi certificate that looks something like this.
Solution 2:
The actual hardware in the router should be fine. The "draft" designation just means that the IEEE hadn't finalized the 802.11n standard at the time the equipment was made. They should be able to change this with a firmware update unless the IEEE makes a drastic change to the standard, which will not happen in all likelihood.
Get what you want if you need it and as long as it's from a big-name company there will be a firmware update to bring it to final 802.11n status.