Performance Chips - Are they worth it, and which ones?

In news:AM3ze.142512$xm3.81408@attbi_s21, Jay stated, which I then commented on below:

Most of the stuff there is Ford with some Chevy.

I used a Hypertech tuner on my truck. Best investment I ever made for this truck. Huge improvement, slightly better gas mileage (about 2-3mpg), and better transmission control. I should have done this as soon as I bought the truck. Hypertech offers two levels of tune. I tried the max power tune. Didn't notice any difference, fuel mileage went down, and it really pinged - bad on mid grade fuel, slightly on premium fuel. So I use the mid grade tune. Even with the mid grade tune I would get some pinging when I did moderate towing (3500#), unless I had premium fuel. So I installed a 180* thermostat and some Water Wetter. Now it runs even better. Last time I towed, I beat it hard on a moderately hot day trying to make it ping on mid grade fuel. Didn't happen. Go to the factory web site and see exactly what the tuner will do for your truck. Ads in most catalogs and sellers web sites list what the tuner can. But some of those features have an asterisk next to them, and the footnote says some features are not available for all vehicles. On my truck, the Hypertech tuner does not allow changing the shift points or adjusting the speedometer for non-stock tires. In short, buy any one of them that meets your requirements. It's the quickest and best improvement you can make.

In news:42cd3c4b$0$52204$ snipped-for-privacy@news.usenetmonster.com, .boB stated, which I then commented on below:

Thanks Bob! Sounds like a plan. I like the write up on the Hypertech. I saw another one called the Edge Power Juice, but that is pretty expensive and would have to get under the hood to remove it if I were to take it in for warranty work. Sounds like the Hypertech III is the one.

Ace