Yeah, like I said, I've successfully stabilized the walkway by digging out and filling in, but it never lasts. Using portland cement the last time helped maintain it for longer than usual, but a couple of them are wobbling again, and I'm getting tired of having to fix it all the time.

I've never gotten good results from asphalt patching, but I've also always used tar. If I decide the concrete isn't worth it now, I'll definitely try that Sakrete stuff (or something like it.)

The thing I like about concrete (for the walkway and the driveway) is that when it's done, I never have to worry about it again, save the very occasional re-sealing. Also, nothing's going to grow up through it the way grass and weeds have been doing in-between my existing walkway sections. It's not going to be easy to cough up $6kish right before a home refinancing, but I only see the asphalt patching/sealing cycles getting shorter and shorter over time as the existing surface continues to wear down.