Hey Crusoe,
Oahu Hawaii has steady wind that pulls like a cable park. The variance in gust strength compared to average wind speed is bugger all and allows for tricks to be learned much more easily rather than in gusty wind. You just don't need a bow kite in Oahu
True Gusty wind is like Kurnell in Sydney in August when the wind is blowing 5-40 knots WSW. True teabagging at it's finest!
Most places have slightly gusty wind. I would think that any wind that has gusts >25% of it's average windspeed could be said to have "gusty" wind. Strong winds tend to be more gusty because the increase in gust strength is relative to the increase in average strength ie
Light winds 10 knts. A 25% increase = gusts of 2.5 knts above average

Moderate winds 20 knts. A 25% increase = gusts of 5 knts above average

Strong winds 30 knts. A 25% increase = gusts of 7.5 knts above average

Crazy wind 40 knts. A 25% increase = gusts of 10 knots above average [}:)]
A 2.5 knot gust is barely discernable, whereas a 5 knots gust is noticed but not making life uncomfortable, just fun. A 7.5 or 10 knot gust represents a full kite size or more difference in the ability to handle the gust which is why it becomes more serious.
And these numbers would be considered only a bit gusty. Depending upon wind direction it can be even more gusty, ie offshore, through mountains, trees, buildings etc all adds to the turbulence.
There's no use complaining, SLE (Supported Leading Edge or "bow") kites have all but done away with the impact of gusty wind. Just buy an SLE kite and gusty will be a thing of the past provided you ride it within it's nominated wind range.
Shoulda been around when we were riding Westerlys in Sydney with 2 line kites

Whoa, sorry, I need some water time. Hope this helps a bit anyways,
Good winds,