Frank, I agree Lee's Ferry is some of the finest big trout fishing in the state, and it's about 4 hours, if I remember correctly, from Phoenix so it's do-able. There are some huge Rainbows there, and lots of them too- I heard the density is nearly 50,000 fish per mile, and there's 15 miles of prime river there.
However, there are some detractors- at least from what I found when I lived in Arizona. Like you pointed out, the wadeable fishing is very limited, and it's a huge, fast river to wade in, at the walk-in section, so a boat is pretty much a necessity. There are no real hatches there. Midges, scuds and San Juan worms work year round, which simplifies things; however, the largest fish tend to hit the smallest flies that can be dead drifted for the longest distance, which is another challenge. The river level fluctuates throughout the day so you'll sometimes be fishing across more than one deep channel, so as not to get stranded on some shoal in the middle of the river- dead drifting skills are put to the test here. Since a boat is required, and a guide is a good idea, this adds money to the endeavor- although the guide increases your chances of success and your chances of NOT ruining your propeller on an unpredicted rock and accidentally being sent down into the Grand Canyon, which is something to keep in mind here- however money is money, and with the economy and gas prices the way they are, this can be a real concern for some people.
The alternative to Lee's Ferry that I found when I lived in Arizona was to fish some of the "smaller", (unnameable on public forums) streams in the Rim area of the state. I have caught 17-22" rainbow and brown trout on woolly buggers from streams that I could easily walk across- though of course it's the deeper pools of these step-across streams that hold the largest fish. Instead of having to use small flies and excellent line control, I've found that little skill is required to catch even large trout in small streams, which I think is because of comparatively light fishing pressure and perhaps also the inherent scarcity of food resources in physically limited ecosystems like small streams.
