I have owned 2 BenQ 1620's since they came out. At that time, Lite-on wasn't nearly as good with DVD burning, although they did CDs very well and extraordinarily fast.
Recently, I bought a Lite-On 1653 because I needed the small size and cool temperatures.
It had retained the extremely fast cd burning, now with much better quality. Surprisingly, DVD quality was much better than the Benq. After some months, DVD quality still beats both Benq.
BenQ, 8% coasters (a DVD with one or more skips). Lite-On, a total of one coaster, ever. That was my fault for overspeeding the reads to 16x. It hates that!
I had originally increased the read speed of the Lite-On to 12x, but because it wasn't as successful as the BenQ at reading, I decreased the Lite-On back to factory defaults for read speeds.
Due to early speed lauch, a Rip at 8x on the Lite-on takes about a minute longer than the BenQ at 16x.
Same story with burns. BenQ factory overspeeds most DVDs to about double the rated speed. However, it lauches 8x writes at about 2.6x and it doesn't reach 8x speed until over halfway through the burn. The Lite-On burning the same disk at 4x, immediately lauches the burn right on 4x and finishes nearly as quick as the BenQ with its overspeed trick. So, on economical media, the Lite-On wins for quality with slim difference in speed.
The BenQ does have early speed launch with 12x burns, and it does overspeed most 8x media to 12x for quick 6.3 minute DVD burns with great quality. 16x burning can be prevented with MediaCodeSpeedEdit as there is a huge quality drop for only a 15 second gain in speed.
BenQ burns cds with reasonable speed, but can't come close to touching the "Lite-On CD attack mode" for speed. Write quality is similar, but because the BenQ is slower on CDs, it makes prettier quality control scans. Yes, it does write CDs with better quality, and it takes its own sweet time doing it too.
Perhaps the biggest difference between the two would be in read quality. The BenQ can read a scratched disc of DVD or CD at maximum and overclocked speed without making an error. That is a BenQ exclusive.
The BenQ is always quiet--always.
Lite-On is quiet with factory firmware and DVDs, but it does have their "cd attack mode" sound on cds. I think it is really entertaining because it is SO loud and a lot of air blows out of every conceivable crevice. You don't hear this noise for long because it is incredibly fast with CDs.
Lite-On is always cool running. That can be important.
BenQ is somewhat warm, so just don't install it into the very top drive bay in your case.
Due to the newly enhanced reliability, lower price, and zero screwups, I would choose the Lite-On. There is a considerable speed difference in specs, but due to early launch, the Lite-On is actually the faster unit on 8x and slower DVDs. It is also faster on CDs.
*However; if you burn 150 CDs per month, I would recommend that you purchase a Sony high speed CD burner. The CD-only unit burns with slightly better quality, is slightly faster, and is slightly more durable. Due to the volume, multiply my description of "slightly" by 150 times.
We have one in our office (red print on front 52x/32x/52x) that has performed flawlessly for several years of rough, frequent use.
They are available in a 100ms latency ($22 Newegg) and in an 80ms latency model ($32 TigerDirect).