The Plextor PX-MPM320U supports an array of standards apart from those associated with HD.
You're likely to encounter the H.264 compression standard and the MKV container format, neither of which are able to be played by the device.
Of course, the VOB-playing functionality is still worthwhile.However, if you're uninterested in HD and in the market for a semi-portable product capable of carrying all your DVD and SD videos, this is ideal. Its 720p upscaling is a bonus.
The interface is clunky, similar to that of the PX-MX500L, but it feels more manageable. Composite wiring and SCART adaptors enable connectivity with most modern televisions, but this is more for the SD man on the move than the HD visuals-are-everything connoisseur.