Ditto Warlock! Duo and Duo2 are 2 of the best chips on the market and have proven to be extremely reliable. I'm afraid you have been seriously misinformed.
If your opinion is based on a bad install or faulty PS2, then blame not the chip, but the installer or PS2. If installed correctly, they are bodaishly awesome and very good. I recommend them with experience of use cause mine is excellent and works perfectly!
Chalk this one up as Extremely misInformed, and now corrected!