I'm also there with ya. I'm running a 2010 802.11N Time Capsule. I'm hoping an Airport Extreme supporting MU MIMO comes out soon. I thought I heard Apple was going to be including support for it in their devices and seeings how it's been 2.5 years since the last router update, it's probably not too far off. That being said, Apple has taken up the strategy that if it's not an iPhone, they're not too excited about updating it very often as evidenced by the fact that the 2015 Macbook Pro 15" still runs Haswell, the iPod is almost forgotten about, and they forgot to update the Mac Pro for like 8 years.