What service are you signed up for?
I have 1500/384kbps ADSL and I get roughly 1280/320kbps on my wired computers (~160KB/s downloads). When I had my MR814 I think I tested my K6-2 366MHz laptop w/802.11b card and it got about the same bandwidth results as my wired computers.
I'll test it again with the WRT54G if you want.