I have no landline anymore. When we first moved into our neighborhood almost 10 years ago, reception was BAD no matter which carrier you used, so I never, ever would have considered going only wireless. Now, service is great (no dropped calls at all since I switched 5 months ago) and our phones keep a charge for several days (we checked this out the first week we had them - now they get recharged each evening before bed).
Definitely set up a regular docking station or particular place to keep the phones, though. You wouldn't want to misplace it and have the ringer off.