I am also intrigued Mutt. There isn't much room for hanky panky in a flexwing
We started a club for microlight pilots in Essex and now have nearly 40 members. Approx 30% are pilots that have migrated from GA, the rest have only ever flown microlights. Some are like Flight Stim and Genghis, who stay current on both. The cost is a big issue and if you fly for fun, you'll get over 4 times the hours in, for the same cost as renting a PA28.
The limiting factor is mostly wind strength. A 20kt headwind does make for a long trip. Crosswind limits are not that dissimilar to many light GA types.
One comment that I often hear is that GA pilots consider they are safer after doing the conversion, as microlight training focusses very heavily on engine out practices. You constantly ask yourself "where will I go if it stops now?" Whilst GA training does have this element, many GA pilots fly as though the engine will never stop. This training goes back to the early days when they were unrelaible. Modern microlights are very reliable, to the extent that I have heard the restriction on overflying built up areas is likely to change to the GA rule, allowing this if able to glide clear.
Another reason many people fly microlights is the comradery (sp?) There are fly-ins almost every weekend through the summer and many clubs/groups arrange impromtu trips, just for the sake of it. GA and heli's tend to go somewhere alone where as microlight pilots often fly in groups.
Generalisations never work for long and you will only find out if its for you by trying it. The lucky pilots are those like Blind Lemon, Fly Stim and Genghis, that do both.
Anyway, here's where we went at the weekend.