... they were designed for use in aircraft and as far as I know do not interfere with any of the other systems. The fact that I decide to use it on a plane that is just a bit bigger shouldn't make a difference.
You are right with your cautious approach....I'm never going to say they are 100% safe because you can never be 100% sure with anything. But personally I don't have a problem with people using them. Mobile phones is a completely different matter though and personally I think they should always be banned. And as for transceivers in the cabin one is probably breaking the law.