A good brush will respond to the contours of a good model, don't overload it and keep your paint thin.
I have Hasslefree models that I haven't been brave enough to paint yet. Their not-Elvis fills me with dread everytime I look at him. It takes time to get it right.
You've already answered your conundrum though! Seriously, the Hasslefree minis are an absolute joy to paint - with your good brush and thin paints, the level of detail on the figures does half the work for you. Face your fears, and enjoy!