hmm... I had not considered that perspective. Previously the bridge was a mere upsell... perhaps I should bundle them together.

Performance Chip + Bridge -- REAL CHEAP -- PM ME

Chip, as in little thing wired into spoof ECU, Bad.

Chip you solder into the ECU replacing the factory ROM, not bad, but not really done any more, certainly not on RX8.

Cobb Good, I have one, love it, but need to have a tune generated for your car. Consensus is not to use the Cobb tune. Only place I know to get one is http://www.mazdamaniac.com/. Custom tune is a process where you are involved. Get tune, test tune, collect data, send data, repeat about 6 times. Depending on where your test road is located, figure an hour a session, a couple of sessions a day. Old processes sucked (email). New process is google talk and interactive, works great. This is the part of the post that will likely generate the most follow on traffic.... pm me for more data.

I know nothing about the other options.

If something happened to this car, my next 8 would get the stuff in my $100 thread (below) then an Access Port Tune.

Way back in 2004/2005 the Camzoomer piggyback computer came out and was fitted to many RX8's. This was specifically designed for our car. It was found that after the car was tuned, the car would slowly loose it's tune and you would be back where you started. The reason was that the car's ecu would see that it was running "out of spec" and begin to adjust everything so that car would run as designed.
Now if this can happen with this piggyback computer, adding a resistor here, a capacitor there or wiring in a chip isn't going to help improve HP or gas mileage. I don't need a test to tell me this. The only thing that these chips may help are dumb 1980's and earlier electronic fuel injection systems that are always open loop.
Why are you being treated harshly? If you do an advanced search on this site, use the term chip and check titles only, you will come up with a multitude of threads that new people come on the site and ask our opinion on. People should realize that if it was this cheap to get more hp and gas mileage, these chips would already be on their car. The manufactures are always looking for ways to get better fuel mileage and hp gives them more bragging rights.

thread closed.

OP either take the advice given in this thread or go try some chips yourself and report back.

no one need to try a "chip" to know if it "works" or not. all they need to know is what the chip does and how the modern PCM works.
next time try at least getting the thread in the right place