When I back up or load a XBOX game it took me around 1.5 hours, from XBOX to PC HD. I am not sure it is normal or too long. First, up load XBOX game files to PC HD (around 50 minutes to 1 hour 15 minutes). Second, load all game files from PC HD to XBOX HD (It tooks around 40 min). Third, fix default.xbe and evox.ini file then load to XBOX (around 3 min). Finally, play the game.
OS in XBOX: EVOX 1.8.3285 PC: Windows XP Pro SP 1
LAN: Netgear FA311
Software:FlashXP
HD: PC WD 160 GB XBOX: WD:120 GB 7200 RPM
No MOD Chip
PS. I think it is better change your XBOX HD to bigger one, from 80 to 120 GB. Before I was worry about HD will overheat but it looks like it is not a problem. I already swap my XBOX HD for over a year (15 months). No problem at all.