Since there are two other threads about external enclosures, I'll post my findings since I had a previous post in this thread.

I swapped both the Benq 1620 (as 162I) and NEC 3500A in my Plumax USB/1394 combo and checked burn and burst rates. I have a VIA-based 1394 PCI add-on card. Although the burst rates looked great, but the Benq burned YUDEN000T02 @ 12x PCAV while NEC burned up to 15x. I only obtained 20/21 MBps with a 812S@832S, so it may seem like that the burst rate can be drive dependent. With either Benq or NEC, the USB was only 15 MBps.

Pictures explanation:
1) Back side of the PCB, seems like a TI USB controller IC.
2) Benq 162I burn.
3) Benq 162I burst rate.
4) NEC 3500A burn.
5) NEC 3500A burst rate.