if you'll follow the link to anandtech i outline the reasons, here they are for the less interested. i have comcast cable at 12/2 and a motorola sb6120 modem and am using the latest firmware (updated two years ago!) from netgear.
1. using a wireless n client (rosewill rnx-n300x) i could acheive 300Mb speeds but my ping time would sometimes exceed one second (not 100ms, a full one-one-thou-sand).
2. adding b/g clients to the mix i get all sorts of dropped signals and my n clients slow down. to keep things working i have to reset the router daily.
3. dropping the transmit rate down to 54 or 144 and still no joy - dropped connections, long pings, et cetera.
4. if you read the reviews on newegg you'll see most users have trouble when upnp and qos are on - turning these (awesome and essential for me) services off as well as all others except for port forwarding i can keep the router running for a few days and up to a week, but it still stops working after a while and i have to deal with what appears to be a "sleep" mode, refreshing pages for thirty-forty seconds before they load.
5. speedtest.net says i get 1-6 down and ~1.2 up using my wireless n client, no other clients connected. connected to the switch i exceed 20 down and 2 up, about what i get connected to the modem. obviously wired will be faster but i easily got >10 down and >2 up with my wrt54g that i picked up from a savers for eight bucks two years ago and my internet was snappy (oh do i miss it!).
6. a lot of people will be buying these as repeaters - it only supports open and wep passwords in repeater mode, dropping your n network down to g speeds as full n requires wpa2.
all that said, if you're upgrading to n from a decent g router you, like me, will be sorely disappointed. if you search outside of product reviews (ie netgear forums) from users who have owned the router for a few days and are really excited you'll notice a ton of unhappy customers, a complete lack of firmware development or support from netgear, and this one moron who works for netgear that swears the router is great and suggests a reset and thirty seconds is the solution to all of your problems. seriously - i'm on my way home now from visiting my family and their b network on a 5Mb cable connection was giving me better download rates and faster page loads then i get at home. heck, with only half an hour of use, i am confident that the connection i'm using now on a greyhound bus is more reliable. don't get me wrong - the wnr2000 v1 works but, at least in my experience, it just doesn't work as advertised or expected.
edit: sorry, yes - i am saying the hardware is bad. this could probably be remedied if v1 supported third-party firmware or netgear still supported the router, but it doesn't except with A TON of leg work and netgear doesn't. however, everyone who got v2 seems to be happy (broadcom instead of atheros) so hopefully purchasers are lucky!
Edited by claes - 1/17/11 at 5:35pm