As of 2018-05-26, TP-Link hasn't updated the firmware for v2 since 2016 and the Archer C8 is not supported by OpenWrt and will likely never be, due to its use of an undocumented Broadcom WLAN chipset. It is therefore unsafe to use this router and will probably always be.
I replaced my 6-year-old TP-Link TL-WR1043ND with a Gigabit Ethernet 802.11ac router bought for 105 CAD (shipping included) from Dell this week.
Wireless range seems to solve the connectivity problem of one of the clients I was experiencing with the previous router. For reasons I never understood well, at times the client would have huge packet loss and even disconnect, even though it is 1 decameter from the router, no other wireless device was active and other houses a several meters away from ours. With the Archer, the worst path has a 0.01% packet loss.
The interface is satisfying (although English-only until you install the May 2016 firmware update, since the router came with the 2015 firmware!). It is simple and the feature set includes most of what I need.
I accidentally pressed the reset button while relocating the router. As noted in this TechHive review, this button could easily cause an inadvertent reset, but I did not push it long enough for that.
I chose this router partly because of its comparatively long warranty (2 years rather than the usual 1 year). I am mostly surprised to find no specification of warranty in the box. The box contains 2 quick installation guides (1 multilingual, 1 English-only), 3 prints of the GNU General Public License (versions 1, 2 and 3), a copy of the GNU LGPL, a superfluous "Resource CD", but no mention of warranty.
Issues
There are a few issues with the firmware. In the first month of usage, I once lost access to the interface until I rebooted.
The firmware features "NAT Boost", which allows to collect bandwidth usage statistics for each device. While this is quite useful, it needs refinement (in particular, the total bytes column is unreliable due to a 32-bit overflow after 4 GiB of transfer).
While the firmware has some support for Dynamic DNS, it does not support my provider (DNSEXIT). After a few months, the interface got unusable again until I manually rebooted.
As of 2017-09-23, the firmware does not support standards-based dynamic DNS update (automatic DNS on a LAN).