While some routers are just better than others, remember that just because your router is capable of 300Mbps, does not mean your internet will necessarily be faster. For instance if you get 10Mbps internet, you will not see a difference in internet speed between G and N. It will top out at ABOUT 10Mbps.
Where routers speed really shine is local network stuff. Moving a file between computers at N speeds is obviously faster than G.
That being said, my Airport Extreme has been a beauty. I set it up over a year ago, and haven't launched Airport Utility once since then. Speeds are lightning fast, and I get about a block or so of range...Kinda flat land where I'm at though.