cough..cough.. [are we in BenQ forum?] cough.. cough..
Okay, let's see if I can educate myself... Few months ago PX-716A WAS superior to Benq 1620 in this area:
1- advanced CD Audio processing
2- Overburn to >4.38GB
3- Write Speed with PowerRec disabled (similar to WOPC disabled)
4- SpeedRead (rip faster than BenQ)
5- DVD-R write quality (both drives show excellent DVD+R write quality on recommended media-TY, MCC, MXL, RICOHJPN.
1 and 2, PX-716A is still superior to 1620.
3 and 4 the other way around now.
For #5, hm.. on TYG02 1620 is much more better, for most other DVD-Rs I think 716a is better.
Regarding quality scan software, I like Nero CD Speed better than Plextools because of its simplicity. Nero, in one pass you can get all PIE-PIF-Jitter, with Plextools you need to do 3 scans for get PIE, PIF and Beta/Jitter.
To sum up, you need to determine your own needs to choose for your second drive. Both drives are excellent in my opinion.