Is there any news on a new release of firmware for the 2860ac range at all?

I'm currently running :-
Firmware Version 3.8.2_VT2
Build Date/Time Oct 29 2015 16:38:04
DSL Version 574307_A/B/C HW: A

But the last few releases just seem to have made the router slower, the wifi less reliable and much worse to use

Please contact support with details of your issue and ideally which devices you're seeing decreased speed with.

The 3.8.x firmware was found to improve wireless throughput during testing so if the update has decreased speeds or reliability with your network configuration / environment, that should be investigated.