After a bunch of researches, today I tried to go and find for a WRT54G v4. I just wanted to try a store nearby and see if there is any v4 left. Really lucky, the first one I picked is a v4 model. Then I tried to look if there is any WRT54GS v3, but all of them are v5, so I picked two v4 model, one of them is used to sell on ebay =) Now I am going to update my firmware. Which one would be better? I would like to switch to GS, would there be any problem? I heard that once you switch to GS, you could switch back to G but after that you couldn't switch anymore, is it true? Thanks.