Table of Hardware: Ideal for LEDE

Undoubtedly there is a lot of passion out there but...I'm looking for the best hardware in terms of CPU /speed memory etc. for LEDE firware doing SQM do counter bufferbloat.

I don't need the WiFi as I have a dedicated Ubiquiti doing that. Really need a wired router. Possibly some folks will have some pointers on reliable machines with fast CPUs and fast memory.

I've thought about trying to use a spare Desktop with a nice i5 cpu, tons of memory, a SSD and a 4xNic but wonder if that is nutz.

Why not an APU2?

I have one running at my brother's, with a few Ubiquitis as APs as well - if you were thinking about a full-blown x86 system, then the APU2 would certainly fit the bill (except it's more compact, and built to be a router).

SQM works nicely on it - I recently enabled a cake SQM instance on the APU2, and it can do 100 Mbps (with SQM) at minimal load (~20%).

Very happy with it!

I have looked at the APU2 and it does seem to be a nice package. I am wondering how much CPU speed might contribute to the ability to control bufferbloat. Has anyone examined this? My connections aren't all that fast, 40 mbps on a good day with a tail wind, but then lots of manipulations are going on with queue formation and maybe a fast CPU would make a difference.

I have 50/10 VDSL2 and my MIPS DIR-860L handles that just fine; however, it's unstable with cake SQM, so I have to investigate, I suppose disabling offloading will influence CPU load.

It looks like you are looking for a primary router to handle the WAN side of your home network. If all the router is supposed to do is handle traffic shaping (sqm) and handle NAT and basic fire-walling. Assuming you do not simply want to buy the most expensive system around, I guess the next question is what bandwidth does you ISP supply and do you envision any bandwidth changes anytime soon?
At your stated 40Mbps even a venerable old netgear wndr3700 would work well as sqm-shaper (it can reach up to 50-70Mbps combined up- and downstream bandwidth), but if you have bandwidth updates planned it might not cut it. Several people are quite happy with the APU2 as @Borromini mentioned, which might be an especially suited device since the maker seems to be quite opensource friendly. Also the turris omnia would fit the bill, except the ideal for LEDE, as they are maintaing their own openwrt/lede fork and do not allow simple installation of upstream lede. (This is not intended to diminish the turris maker's work, the fork seems like a reasonable compromise for them to be able to fully support theit customers, but it simply does not merit an "ideal for LEDE" label)

Best Regards

also one should not forget the various embed x86 boards out there.

for example

may no offer the same roubustness/longlevity as our trusted wrt-style hardware, but has a lot more cpu cycles, broader busses and advanced cpu-instrucion sets (e.g. aes-ni for vpn) and options in general.

1Gbit/s samba will also run smoothly ...