There are other considerations.

More than a year ago, I bought a Uniden system, which immediately irritated
me with its poor design and confusing operation. I replaced it with a GE
(Thomson) DECT 6.0 system, which was much better thought-out. The controls
on the base unit are well-grouped and have different shapes. I never have to
refer to the instruction book.

The hand units have an excellent speakerphone. Unfortunately, they use
shrink-wrapped AAA cells. However, making up a new pack is not out of the
question.

Don't buy a model where the "base unit" is a hand unit sitting in the
charger. There are times when you have to tuck the receiver between your
head and neck.

You should look for a unit whose base station provides basic functions when
the power goes out. "But I have a cell phone." Not if the transmitter also
goes down.