Thank you all for your replies!
@L&LD ,
@Volt , looks like we have very diametrically opposed positions, or as the expression goes, maybe we can agree to disagree.
I spent substantial time on the forum and Google and was unable to find anything recent that
quantified the performance differences. Dong's review of the 58 was probably the best, but did not include speed tests of the 56. There are no 2021 reviews of the 56, and all the 2020 reviews claim these to be draft devices. Most forum discussions are "just don't do that".
@L&LD, if you have some gold here, please offer a link.
What is really missing IMHO, is any discussion regarding the fact that the 56 has a Quad Core CPU as opposed to the 58 Tri-Core. The 58 has a separate 5Ghz wifi chip to get to the useless 160 number, which I expect, along with marketing and antennas, accounts for the the higher price. I have read the Broadcom spec sheets on the 2 CPUs, but find marginal differences, cores aside.
It's probably worth noting that I am an IT manager and have been in tech since the early 80's. I build computers and small home and business LANs on the side. I am regularly replacing old wireless N routers or ISP provided gateways, and have been doing so with the AC68U for the last 6 months as it's easy to expand to a mesh system if needed (has not been) My clients are not complaining about 30-50 Mbps wireless speed, the only complaints I get are that their wireless (N) does not adequately cover their space or they don't want to keep paying the $10-13 month for the ISP hardware.
@SomeWhereOverTheRainBow , really not following your comment. This hardware does 2 things, its a "router" and a "wireless AP" in one box. Better wireless tech does not technically make one a better router.
Both of these are close to the CPU speed of the AX68U (1.5 vs 1.8) and have more cores, and the same amount of memory & flash (not clear on their tech DDR3\4 etc). The cores alone should make either of these a better ROUTER than the AX86u (ie better task handling). As for 2x2 vs 3x3, while the landscape will eventually change, there are very few 3x3 devices that are not extreme PCs. Not finding evidence that a 3x3 Router's AP will make a 1x1 or 2x2 device perform better. I am open to being wrong here, just need some supporting data.
My personal use case is testing, mostly range; however if I can position a AX vs AC device to my clients for the same price, it's future proofing them. I expect all of these will do the task of ROUTER, but I could use a new wall mounted device in my personal tech closet. That's the drawbacks to the AC1900P and AX68U. Wall mounting generally leads to better performance (higher) in office locations. It's also helpful in homes where the ISP comes into a basement. VPN performance would be all bonus though; in a closed test environment I get about 35 Mbps on my AC1900P if I recall (OpenVPN Server) and it's nice to be able to offer this to my small business clients.