Any Expertise Out There?

I have been contemplating purchasing one of these for relaying information. I know that I can get them in Pattaya and Bangkok. I am considering a multi-line unit which is for inside the window. Before I part with money for one here and then find out something later - I am asking now if any of you good lads out there have experience with these things and can warn me about the pitfalls when purchasing. E.g. How reliable are they? What's the easiest method to 'feed' the information? Is there a point where they are too expensive for what they deliver as in number of lines or number of characters or rate of flow of information? Approximate cost in West. And so on and so on....

Any information would be greatly appreciated.