The old system was an AT&T SL82118 with SL80108 handsets.
With that in mind, I bought a new Panasonic KX-TGF383M with three KX-TGFA30 handsets for $110 (on sale + tax). This thing does more things than I can comprehend, but best of all, the handsets come with ordinary LiOn batteries. Yay. Batteries will be easy to replace when they conk out. (That's assuming that the handsets don't conk out.)
What's new and cool about the handsets? I have no idea.
What's new and cool about the base unit? I have no idea.
Oh, wait, it lets you use your cell phone as your phone line, so you can use your cordless handset to dial out, using bluetooth, through your wireless account. That is so cool and just about the most useless feature that I ever heard of. Wouldn't it be more sensical to let you use your bluetooth phone to answer calls on your landline? Otherwise, I'm left absolutely mystified at the target audience for this feature. And given that your smartphone may be using your wifi to talk through your internet connection, isn't that just some roundabout VoIP system? This give me headaches.
I'll watch some videos on the system to see else it does. Maybe the reviewer can make some sense of it for me.
Other than that, the base unit has an answering machine, and it appears that you can just pick up the handsets and dial out with them. That would be amazing. I hope that dialing is simple. I generally expect that modern technology will take anything simple, add a ton of options, and return little to no value. (How does more choice lead to less value? That's actually a very interesting question, but too much right now.)