Just pay attention to the numbers. Firmware updates originate from dsgba/N-card (www.superdslink.com) and the clones nominally rebrand an exact copy later (sometimes they @#$& up though). The difference between one cards version of firmware and xmenu is essentially the default background picture. If the clone release has some real effort in it, the auto-generated config file will include the clone homepage in the header...
At the time of posting, Firmware 1.45 and x-menu 2.53 are the latest.