WiFi deadspotsSome devices not being responsiveConstant disconnects and reconnectsone thing can fix all 3 of those... REPEATERS.. cheap and dumb... all they do is procreate the signal.
far as routers go its first come first serve.. 1st on get 100% bandwidth... second on its a 50/50 split.
load balancing routers are specifically for dual isp connections... example taking 2 cable connections and making sure both are equall...
depending on what kind of speed you need, its nice to hear someone complain of 100 megabit when all I had is... 5!!!! on dsl lol... but any way technically as long as you configure the router to however many devices they will all work at the same...
using my old wrt54g I just put it in bridge mode, although I replaced the normal bios with dd-wrt which totally unlocks the potential of the router. bout only other thing is make sure there both wireless g and make sure the modem ethernet cable ...