I just got my new ECUTEK Delta Dash ecu monitor hardware and software, and it is phenominal. It seems to have all the functionality of the Subaru Select monitor, while reading data MUCH faster! You can read all the Subaru specific data like front a/f sensor voltage, injector pulse width, EGT, knock correction, etc. You can data log all variables at rates exceeding 10/second, and the output graphing is very user friendly and readable. One 10 minute run and I know more about how my car is functioning than I have since the day I bought it. It's a bit pricey, but given the data that's available, and compared to the competition, it is a true bargain. The ECUTEK people are a pleasure to do business with, as well. VERY highly recommended.
Their website, for those who haven't heard of them already, is: