I hope to have a document comparing it to docsis 3.1 pie at some point in the next few months, in the meantime, I hope more (especially ISPs in their default gear) give cake a try! It's open source, like everything else we do at bufferbloat.net and teklibre.
My Netgear R7000 can't handle my 400mbps connection using qos throttling. I will need probably at least a mid range Ubiquiti router to handle it.
Avoid modems with Intel, specifically the various "Puma" chipsets. Best to double-check the spec sheet on whatever you buy.
The main alternative seems to be Broadcom-based modems: TP-Link TC7650 DOCSIS 3.0 modem and Technicolor TC4400 DOCSIS 3.1 modem (of which there are a few revisions now).
$69 MikroTik hAP ac2 will easily push 1Gbps+ with qos rules - https://mikrotik.com/product/hap_ac2#fndtn-testresults (it's a bit more tricky to setup and you need to make sure you don't expose the interface to the internet)