The AC1900 First Look found that the R7000 and RT-AC68U both provided a slight 5 GHz performance improvement over the top AC1750 router (ASUS' RT-AC66U) and NETGEAR's AC1750 R6300. So I ran a quick comparison against the two again to see how the EA6900 fared.
The downlink comparison shows the EA6900 besting both products by a healthy margin, especially the R6300.
EA6900 5 GHz Performance Comparison vs. NETGEAR R6300 & ASUS RT-AC66U
For 5 GHz uplink, the EA6900 again spanks the R6300, but has only a relatively narrow performance margin over the ASUS. Remember, to achieve any of these high throughputs, you need an another AC1750 router in bridge mode or ASUS' PCE-AC66U or PCE-AC68U PCIe adapter.
The EA6900 ties for a #2 rank with the ASUS RT-AC68U among the three AC1900 routers ranked. The ranker detail shows the EA6900's main weaknesses are vis-a-vis the other two products are routing throughput and 2.4 GHz range. Of these, I'd say 2.4 GHz range is the most significant, since 800+ Mbps of routing throughput shouldn't hold many of us back.
EA6900 Ranker Performance Summary
Although not included in the ranking score, USB sharing throughput isn't exactly a product high point either and needs work. And Linksys engineers may need to check compatibility against different USB 3.0 chipsets (specifically the JMicron JMS551 USB 3.0 to dual SATA 3G bridge used in the Startech dock I use) while they are at it.
But it's still waaay too early to buy any AC1900 router anyway. Especially if the main reason you're opening your wallet is to try to get a 600 Mbps link rate in 2.4 GHz. Drivers are not yet stable, there is only one (desktop) client capable of producing this link rate and it doesn't yet have a driver that enables it to do so. If you need more convincing, read this commentary.
But early-adopter lust is seldom logical (what lust is?). So if you simply must have an AC1900 router for whatever your reason, I have to say that NETGEAR's R7000 is the way to go right now.