I was on JET for three years. My particular BoE kicked people out after two, but I got a special exception because they didn't inform me about the two-year deal. No idea how people like Mystic get five. :p
As for Interac, glad to hear a couple of you have good experiences. I was soured a bit from my "experience" with them. As JET was coming to a close, I had my hopes up about replacing the high school ALT in my town, as he was leaving that summer. I applied for Interac, thought I did everything right, but was outright rejected. No feedback, no reason as to why, and I was left kind of wondering what sort of company doesn't even respond to emails requesting at least some sort of feedback to help you realise where you went wrong with the application process. So no, Interac in my mind is not a nice company at all; but as I said, it's good that people have had positive experiences with them, as they are a big company with a lot of ALTs working for them.
I guess the one thing I learned from the experience was that you should never assume that just because you had a job doing something you are not guaranteed to get a similar job, even with a decent skillset.
As for JET being competitive, that's news to me. Maybe in America it is hard to get accepted, but I found the application process to be very easy, painless, and rewarding. It didn't appear to me as if too many people were interested; and in fact, they told us that each year, fewer and fewer applicants were even applying, making positions really quite easy to secure.
There are a lot of small companies out there. Never come across any advertisements from Altia Central, but then, there are probably a lot who don't advertise greatly, or even along main channels. You just have to have a backbone of steel when heading to a foreign country in the hopes that the company you are working for won't prove to be your ruin. Not to scare lamerobot44, but it's best to be extremely cautious, and always be prepared for the unexpected! The best advice I can give is to be both flexible and enthusiastic, no matter how you feel at any given time. :)
Edit: I had to point this out, also. "my wife and I's intention" should read "my wife's and my intention" or "our intention". You cannot make the first person subject possessive with an apostrophe and no form change. You'll blow up the English language. :p