This one has lightscribe. I think one advantage of the lg over the sammy is that the former copes with DVD- ram disks as well unless I am mistaken (this might account for the relatively larger size of the lg, as the ram discs are bigger than the normal DVD discs).
ram discs are only metaphorically bigger than regular single layer discs in that they have a larger capacity (8.5gb instead of 4.5gb). the discs themselves are physically the same size as any regular dvd media so the ability to utilize dvd-ram media has no bearing on a drive’s physical size.
Well, the ram discs which come with my panasonic DVD player are bigger I think. If I remember rightly, they come in an enclosed case (I have not used them since I got a skyplus box, so will check when I get home this evening)