i juz got my archos 605 wifi, but it's the 4gb flash edition which i put in another 8gb SDHC card for expanded memory.. loving it, the 800x480 resolution screen is absolutely gorgeous and the touchscreen interface works very well.. battery life wise, i'm getting around 4.5hrs but it should reach around 5hrs once the battery has gone through another few more charge cycles..
paying the extra $$ for plugins like opera browser does kinda suck, but then again i don't really use it for web browsing (i have my htc tytn II for that).. as a PMP, the archos is one of the best you can get now.. i'm just keeping my fingers crossed for Archos engineers to write a plugin that can support .mkv files