You should absolutely go with the 350 if you can, the 260 has given me nothing but problems.  It picks up major RF interference as you can not seperate the antenna from the base.  I've had to actually take the antenna off completely to get it to work in the next room but no farther.  Swapped for a 350, remotely located the antenna and I was able to control the system from anywhere in the house.  I've been swapping 260's for 350's consistently.