"Broadly speaking, configuration, task entry, task editing, zooming, and panning are much quicker, and less verbose."

I would quote those points as reasons for preferring SYM! The biggest benefit being the total flexibility on the configuration of the map pages. I find it better than XCS in all those ways except panning which is equally easy in all touchscreen software.

When I bought iglide lite I didn't like the interface and the screen wasn't bright enough. I have never tried the full version on a recent iPhone. No-one at my club uses it.