Would this network benefit from upgrading to N?

Hello,
I have a WRT54G as my base router and am looking to add a 2nd router to my network to provide access for the occasional times when I need to get online with my xbox360 or my Dish DVR (They are too far away to run ethernet cables).

My house is a 2 story and decent sized, my home computer has a gigabit ethernet card and i have 2 laptops that connect both have wireless N capabilities. My ISP supposedly provides 15 Mbps. I have good signal strength throughout the house currently. i don't do many file transfers between computers.

Since I am making the effort to add a router, I was wondering if there would be a noticeable performance difference if I replaced my WRT54G with an N router and then used the WRT54G as my secondary router/repeater bridge for the 360/DVR ... or would just getting a second G route to act as the bridge result in roughly the same performance? If I would notice a considerable difference with an N router, would a gigabit version be worth the extra cost or would any N router do?

Thanks in advance for your comments!

If you are planning to use a G router hanging off the N router, you will just be connecting at the speed of the G router. If you want faster performance, get a an N-based access point and hang it off an ethernet connection. Or get an N router and a N wifi extender to connect wireless if you can't get a cable near where you want wireless.

Gig ports are only good for internal data transfer, if you don't copy files from system to system won't do you any good.

If you plan on using a G access point for wireless, having an N router is useless, need both to be N.

There is as big speed increase from using N over G, as long as the devices all support N. If you connect the laptops to the N connections, you can leave the G router on all the time, won't affect anything. I though you were saying you wanted to extend the range of your wireless using the G connection, in that case everything connected to that will use that speed. If you keep things on the N wifi, they will run at that speed.

Should be OK, TP-Link stuff seems to have mostly very good reviews.