Indeed - I'd be going for 17.01.5 or 18.06 before anything else, on grounds of not wasting time with older releases when a more recent stable is available and will give good service longer into the future; whilst acknowledging lantis1008's view on tool usage itself of course.
tomsmi: Just in case you may think it's quite a job to upgrade to a new release version - upgrading OpenWRT to OpenWRT is usually far less painless than converting from Factory/Stock firmware - dramatically so on some models - don't fear it. Usually it's done before the coffee is brewed and with zero stress, no messing with buttons, no renaming of files or anything that was a pain the first time around.
At worst, you'll need to unplug the router and connect to your flash-admin machine, in case the newly flashed version conflicts with an existing IP on your network (usually 192.168.1.1)
As a bystander to the thread, at least initially...
A casual user could be forgiven for believing they have the most current version when casually using a search engine...
My own search result boldy state:-
" Latest Chaos Calmer Release - OpenWrt 15.05.1
The most recent Chaos Calmer version is OpenWrt 15.05.1, the first service release of the OpenWrt 15.05 series." - source: https://openwrt.org/
and a casual glance at the (incorrect/archived) "old" TOH page https://wiki.openwrt.org/toh/tp-link/tl-wr1043nd states 15.05.1 is the latest release for that model. (I am well aware of the reasons for the old wiki falling out of date and the merger overhead as well as sever forum problems) As a veteran OpenWRT user, the first few pages of search engine results point to old wiki pages I've bookmarked over the years. The first occurence of openwrt.org occurs on my third page of results
Combine that with opkg list-upgradable showing no updates and it's understandable the casual user would assume everything was fine and nothing newer was available.
Thinking aloud to myself here:-
First: an important concept to put across to users is that it's vital to re-flash to perform the equivalent of an OS upgrade, compared using a desktop or server distro Linux package manager to do so (albeit usually in a "special", one-off way) for upgrades to a major OS version.
Second: clarify the status of each release in unambiguous terms on the main page of the project
Third: make the old TOH wiki "archive only" warning appear several times throughout each page to increase the impact of it.
Fourth: make the warnings on the old TOH wiki include a link to the device on the new wiki, to make it fast and easy.
Fifth: ensure new TOH page warning always link to the latest supported stable images automagically.
Sixth: find hundreds of people with the time to implement all the above while doing eveything else too
In the case of the OP, there are no hardware reasons (eg: 4/32 issues) that prevent a more recent release, and I'd strongly recommend it for reasons of general improvements alone. Fiddling with an old version could be false economy, though I bitterly understand the mantra of "never touch a running system"
Personally, I spend 99% of my time on the hardware pages of the old TOH, simply due to the prevalence of low-level hardware information and PCB photos on there. As a longterm user though, I instinctively know what to ignore if it's out of date.
Ironically, in the time I''ve spent on this reply to the thread I could have knuckled down and clarifieded the Wiki a little