is it a performance problem or a freeze?
Performance so far. However, the performance decline is so frustrating that I may not be giving it enough time to freeze completely. This week I made it to 1 day 17 hours before performance was unacceptable, but it also was not at the very poor performance it typically reaches and I did not give it a chance to get very poor since I'm back on my routine of rebooting when performance begins to decline instead of waiting until it's practically unusable.
I need to describe this very carefully so it's properly understood. I did not allow the performance to get as bad as it has when the router becomes inaccessible, and my reason is that because it progressed more slowly, I had to deal with poor performance for many days (rather than a quick downward spiral over a period of 12-36 hours and rebooting) and I eventually couldn't cope with it any longer. Again, performance was well below normal, but it had not yet reached the 10% chance of having a webpage load as before; it was at about 50-60% chance of having a webpage load but I was dealing with having to refresh pages for many days and I couldn't bear dealing with it any longer since the performance problem obviously had not gone away. If I had the patience to wait until what probably would have been 25 days of uptime (with 22 days of declining performance) until I reached that common 10% success rate, I would be able to check if the router had frozen...it's painfully frustrating to know how to restore performance so easily yet force myself to suffer through an awful internet experience. I'm surprised I made it to day 10 instead of rebooting at day 3, when it first became problematic.
To reiterate, I did not have any performance or lockup problems with firmware 1.21 with DNS relay enabled and although disabling DNS relay appears to have helped, I believe that it's a partial fix for the symptom rather than a fix for the problem. It still feels like a memory leak since I only made it to 1 day 17 hours this round despite DNS relay being disabled.