I HATE the Tiger rebate schemes and I think $79.99 is about $10.00 too high for the 1620 including software. So, although I really like the 1620 drive, I voted "none of the above".
In contrast, there seems to be a fair number of unhappy Plextor users based on a recent poll:
http://club.cdfreaks.com/showthread.php?t=119451
Out of the 44 people who voted, 13 were disappointed, and of those 13, 7 warned against buying it.
Here's a comment from OC-Freak, Senior Admin:
I've now done many tests and the PIF's often exceeds 4 - while PIE still being good.
Also got several coasters (Prodisc.R03, RitekG05 and VDSPMSAB002) - so considering the price I'll say Poor Quality compared to NEC/BenQ.
If you get the plex - stick to the highest quality media like TY or MCC to avoid problems
One other drive that a LOT of people like is the NEC 3500. You might want to consider it as an alternative as well - particularly if you plan to write a lot of "-R" media.
The BenQ 1620's real strength is with "+R" media. Many people believe that if you restrict it to "+R" media that it produces the best quality burns of all other burners.