Thanks for all the feedback.
Burden: If you are not building them as beautiful as above additional ,markers clutter your table, and for me it always looked strange when a insurgent just appear out of nowhere on the table...
I'm generally not keen on counters etc on the table in any game. Hotspots can be almost anything, even a building in theory. You can use almost anything you like that would fit in with your own setting.
As for appearing out of nowhere, I think it fairly well represents the uncertainty for 'regular' forces of where the enemy is. Certainly for my Somalis it recreates the lack of local knowledge the US forces have. 'Blackhawk Down' seems to give a good idea of this (I know its a movie, will all the limitations that imposes, but looks pretty convincing to me) with civilians and insurgents all over the place.