It depends on your needs, if your network is largely wired and the wireless clients are mostly just surfing the web, then a cheap gigabit router with 802.11g or N150 will be enough for most people even today.
pretty much all gigabit routers provide the same LAN to LAN performance.
While WAN performance can vary, unless you are using a network like google fiber, the WAN performance will not be a problem for most people.
Even with 802.11ac if you look at the benchmarks on this site, it does not even come close to gigabit LAN performance, so you are not likely to be transferring 5 TB of data across the network via wifi.
And if you need to stream 1080p content then it is important to understand that you do not need N450 or ac1300 to do it. (Most HD streaming over a LAN uses around 10-13mbit/s and bluray content may pull upwards of 30+mbit/s And unless you are running multiple bluray streams, even basic 802.11n networks will handle it just fine.
The only thing I can see a person who likes streaming HD content over wifi, is a dual band router (simply because you can have the streaming device on either the 2.4GHz or 5GHz band (does not matter which, both offer enough performance), then using the other band for general web usage to prevent problems with the HD stream.
For a while, I used a WRT54GL and a cheap gigabit switch, before upgrading to a WNR3500l which offers more than enough performance for my LAN needs and for supporting my verizon fios connection (PS if you move to fios, have the tech install the ethernet connection, if you do not request it, they will have the ONT use coax and you will have to run your own ethernet (the crap verizon router can then be set as a moca to ethernet bridge and connected to your new not crap router.