I have an old Panasonic cordless that I want to replace as well. It still works, but the LCD displays on the handset and the base are failing (only about half of the display is readable.. the displays are losing contrast).
I know this isn't answering your question, but a month or so ago I was researching new phones and I eventually gave up because there wasn't one product out there that had all of the features that I was looking for. One thing that I want is a wall-mountable phone, and although most are wall mountable, their bases are actually designed to sit on a horizontal surface, like a desk or table. When they're mounted to the wall they base is mounted horizontally, which juts out from the wall, and the phone sits in it vertically. Very stupid design, and I don't want that.
Me, basic stuff. Quality phone without a teeny-tiny handset. Caller ID and answering machine. Mostly though, I want to mount it where the current phone is; on the kitchen wall, and it's gotta be one of the bases that's meant to be mounted vertically. Not one of the types that I described above.
I have been looking at the Panasonic KX TG6413T. There is just too many phones out there with too many options. I like Panasonic because that I what I have been using for 6 years and remembering Panasonic was rated the best by Cnet as far as not interfering with other electronics.