AW-Q170A is an AD-5170A/AD-7170A, and that line of early Optiarc drives is not as well regarded as the AD-520x/AD-720x and newer. They had middling burning quality and not-great reading performance for poor-quality discs (though they still perform like every other drive when reading the average, good-quality disc; this made them great transfer rate test drives).
They (7170 and variants) also retained some of the issues from NEC's later drives, where certain non-NEC drives drives fail at full-speed reading of discs written by a 7170, due to the relinks that happen during every DVD burn (as part of the OPC). This issue may have remained in the AD-7200, but didn't seem to cause anywhere near as much of an issue (which, admittedly, was a small issue).
Nevertheless, an AD-7170A is not as worthy of your money as the AD-7200 would have been.