Linksys E7350 OpenWrt install

I'll just point you over here:

The e7350 has this patch, and on my e7350/rt1800 running 23.05.2 or snapshot, I can achieve the max my 1 Gbps line can offer.
I use cat5e or cat6 cables.

I cannot recommend making a judgement on what a chipset is capable of based on your experience of a release candidate.