I have a Verizon N router located in my basement and I get around 50Mbs wifi speed with my macbook air. As I move two stories up, it decrease to around 8 12 Mbs. What would be more beneficial upgrade, adding a 2nd router on the second floor (via Ethernet AP), or bridging a new 802.11ac router next to my Verizon router. Note, we use sharing for itunes & iphoto and want to improve this throughput if possible.
The first thing to do without additional hardware is to relocate your router to the first/middle floor if it's possible.
That would be challenging since I do not have an Ethernet line going to the first floor. Also, the Verizon router is in the basement because I can hard wire it to my home theater equipment.
or if you're really obsessive, run a cable outside, put a high power repeater in a heated box. I almost did that when I lived in a house. You can provide wifi to the entire neighbourhood!
I guess what I'm really asking is: what would provide more "bang for my buck", extending my range with another n router, or "replacing" my existing router with an 802.ac....
It depends upon how thick your walls and floors are and the material they are made out of. Every situation is different. If you're handy, try to run some ethernet cable up to the main floor. That's what I would do. Good luck and have fun!
As a general rule, more access points are better as the signal has less chance to degrade. Add an AC bridge upstairs to cover the upper floors. Connect them via Ethernet not wireless.