Wireless N router suggestions

I would not recommend an AC model unless you want to upgrade your adapters to AC. The ASUS RT-N56U and RT-N66U are both best in class N routers. Take a look at their features and performance HERE.

Wireless is always going to be less desirable than wired connectivity for HD content streaming. You should at least consider MoCA or powerline networking to augment your existing wireless. An expensive router may not provide any improvement.

Are you using 2.4Ghz or 5Ghz for your HD streaming? 5Ghz will require close proximity to the router for good throughput. A WIFI desktop in a bedroom three rooms away probably won't stream much better than your current router.

Since you were already pointed toward SmallNetBuilder, they had an interesting article which says that an AC router will improve even N devices -> article. It was a surprising finding to the author and to me....

While the ASUS AC routers may provide some improvement (albeit small in my testing), I do not consider the price premium reasonable. Moreover, most of the gains are obliterated if you are in close proximity to a number of other networks. And, I would say that article cited that I read when it was published only shows a very modest improvement in most cases and the results are a bit odd IMO, as the latest AC units sometime underperform the prior generation, which may be a firmware issue. And they did not have the issue of multiple competing wireless networks: "there were no other networks active during testing," which is totally unrealistic and my personal testing says that matters a lot.

There is no future proof in wireless at present. ASUS announced a new AC2400 in January and then pretty much bailed on it with an AC 3200 this summer. The prices for most good AC units are so high that it would be far cheaper to buy a good N router and use it until you are ready to upgrade your adapters, not to mention that at the faster AC rates there are NO or maybe one wireless adapter even available that matches the speed of the router.

If you really look at the technology behind AC, it is all over the place depending on manufacturer and IMO is a dead end once heavily adopted as there is really limited bandwidth available with few channels usable and channel bonding required for the higher speeds. Hopefully, you are not in a large city with a significant controlled air space, which shuts down a number of your 5GHz channels that are critical for AC.

There will be something next, but that is a ways off and unpredictable -- maybe it will be a better AC, so IMO the best course now is to optimize what you can do now with dual band N in most cases.

Now if you want to run a pair of high end AC units for a media bridge, it is very useful (and very expensive), but an Ethernet cable to an N AP is far more cost effective. I've installed a dozen or so of these dual AC unit setups where money was no object (like docs with big homes) and the results are excellent, but that comes at a cost of lots of $$.

Practical high quality and best possible perform slightly different, but at a very large cost difference.