Because I'm bored...

Archer A7

• AC1750
• 3 x 5 dBi
• 28 dBm
• USB 2.0
• Single-Core

DIR-859

• AC1750
• 3 x 2 dBi
• 20 dBm
• No USB
• Single-Core

 EA6400

• AC1600
• 2 x 4 dBi + 3 x 5 dBi (internal)
• 24 dBm
• USB 3.0
• Dual-Core

Unless I'm misunderstanding how my devices are reporting link speeds, I don't think I have anything that really takes advantage of the 300~450Mbps or 1300Mbps Wi-Fi speeds.

Found-out that while USB 3.0 seems to make a significant difference in NAS performance, the only stock options are SMB 1.0 or FTP - neither of which is particularly secure.

I have no idea if the dual-core BCM4708 in the EA6400 performs any better than the single-core QCA9563 in the other two.

I'm not super-familiar with antennas, but it looks like the DIR-859 would be best for an open area with no obstructions, the EA6400 is more directional but also has more antennas and beamforming, and the Archer A7 is a bit of a brute-force approach.

So of the two places I'm deploying to, I think it makes sense to have the Archer A7 in the larger home with the most obstructions, and then the EA6400 in the smaller open area where more devices will be accessing it at once.

Finally, install DD-WRT on the EA6300V1 (no OpenWrt because Broadcom, apparently) to effectively make it another EA6400, and there's my backup. Test the DIR-859 in the larger/obstructed space for science before giving it away, and... Yeah, that's the ticket!