Hi Denise!
We are a family of 4 (kids 6 and 2) and recently stayed at a "monorail resort," the Contemporary. If you can fit it in your budget I say go for it! The monorail routing system takes you thru Magic Kingdom, Epcot, Contemporary, Grand Floridian, and of course the Polynesian.
To me, it always seems Magic Kingdom and Epcot generate the most traffic. Taking the monorail vs. catching the bus will cut your travel time in half at least, once you factor in stop lights, slower moving traffic, and just pulling into and out of the resorts that the buses must go through.
My children love the buses, but catching the monorail was like a ride at the theme park for them! It sort of increased the "WOW!" factor...
And although Disney has a really good bus system, sometimes you'll find yourself waiting a while for that bus with your Resort name to appear. We never seemed to wait no more than a few minutes to catch a monorail each occasion. It especially helped with our "antsy" 2-year old (smile)
Good luck with all your Disney planning!