on the E2500 v1 I been running
dd-wrt.v24-43028_NEWD-2_K3.x_mega.bin
on the daughter's router. I have their silly modem in bridge mode so the E2500 does it all.
They have lots devices iPhones, couple different tablets the 4 yrold is on all time and a smartass TV that is streaming sompin all time.
Ain't had any complaints so AFAIK it has been great. I know it is all good when I'm there.
Main reason for it is because the silly cable modems WiFi was shit and she couldn't get good signal in her bedroom...
...the oldass E2500 w/DD-WRT took care of that and other problems just fine
I tried flashing from (the web UI in) Firefox and it worked!
Followed up by flashing the remaining two version upgrades (from Firefox) and they worked as well!
Weird that Chrome worked for the first two upgrades but no more (and that TelNet Lite on the Mac didn't show any errors).
Yes, as I repeated earlier the recommendations on what web browser to use don't always work. Or they work for some people but not others. It is possible that different add-ins in different web browsers are affecting this. Also it may change when using a Mac vs a PC to do a web update. I'm glad FF worked for you. It's a good reminder when a web update fails to try a different browser.