I think some of the comments about the Ford's behaviors are partly because the V10 is a high-revving engine by nature, and so it's very obvious and occasionally annoying when it does downshift. An engine with ten cylinders whirring away at 4000 rpm a foot from your knee is not subtle. The transmissions themselves work fine, and act as most any reasonable automatic acts. There are times when using the cruise control, when they will decide to downshift about when one reaches the crest of a hill.
The older four and five speed Ford transmissions (which are pretty closely related designs) have a rather sizable jump between the two two gears which are, of course, the ones that mainly get used for highway driving. The new six speed is an improvement in that regard; the gears are more evenly spread out than on the five speed.
I don't find my '98 class C, built on a Ford chassis, particularly tough to handle in winds. It does get blown around some in side winds, as would any vehicle with that much cross-sectional area, but I haven't found it unexpectedly hard to manage or ill-behaved. There does come a point with most any vehicle where it's wiser to wait out very high winds, and that point does come sooner with tall vehicles.
Probably the best way to answer your questions would be to test drive the motorhome you're considering, preferably over some varied terrain.