LG seem to be lagging behind, it ofcourse can't get too carried away as the 16x DVD-RAM standard is yet to finalised ?
I assume that NEC would just need to make a new Firmware for the new standard.
Also there is no hurry yet as it will be ages before there is any media that will burn @ 16x.
It will become a media at that speed, there won't be any need for +-RW disks
I also see a mention of the 5173B this might be the 16x model.
It may pay to wait a little for the new standard to finalise and the new drives to appear.
As the 5165/67/68 might be very short lived models.