G is 54 Mb/s max, <= v.4 had Linux firmware, v.5 is VxWorks, GS can achieve higher throughput (can't recall exactly how much), but only with the same equipment (meaning if you have another D-Link/Belkin etc. router crap, it won't achieve speeds > 54 Mb/s), GL is 54 Mb/s max and is guaranteed built upon a Linux kernel. I'd go with a GL, if I were you.