yes, they can be annoying if being used in an annoying fashion by normally annoying folks.
that said, we have used ours for 4 or 5 years now. our first pair (we're on our third iteration) were a mother's day present. i thought them an incredibly stupid mother's day gift, but once again, dh knew better. we used them the following month at wdw and they allowed us to separate with the kids to meet conflicting preferences and then join back up together without a fuss. they also allowed me to take our then infant to the room for a nap and rejoin him and the older boys at a park by "calling" him when i returned the agreed upon park.
on last march's 7-day, the radios allowed us to go into st. thomas and st. martin and still be able to communicate with the boys on the ship. not that we needed to, but we did have the boys radio us once we were in town to make sure they would work...and they did.
my dh is the king of all things electronic. we have the newest motorolas with the 5-mile range, lots of channels and subchannels, and all the bells and whistles. imho, all that's not necessary, but it makes him happy.
go look at the motorola website. when we bought ours late last year, they had a rebate going. and...office depot had a free gift card on top of the rebate, so basically we got one for free. i think i paid $75 each, but got back $40 from motorola and $50 in gift cards from office depot. if you've got the time, keep your eyes out for these types of deals. they happen more than you'd think.