I just got done using the paint pen from British Atlantic. For true chips, I found it to be good. For little scratches and scrapes, not so much. The problem is it goes on like a thin putty and is dull compared to the shine of the regular paint. The end result when you look right at it is that it's noticeable, you can see where you applied it and the line of the old scratch or scrape. Also, the tip started to dry out quickly and I have to wonder if it really is only going to be single-use. I did buy clear as well, so maybe that will make a difference. My thought is to let it set and then go back over it. Later, buff it out a bit and apply the clear. Probably buff it out again and see how that looks. Maybe wash and wax the entire truck and see if that gives it a more uniform shine.
Bottom line, on exposed aluminum chips, the paint is less noticeable then the chip. On minor scratches and scrapes, the texture and lack of shine makes the paint repair more noticeable than the damage.
Update: Got some buffing compound and applied it with a micro-fiber cloth. High spots totally gone and the touch up paint blends in so it's no longer noticeable. I have yet to put on the clear paint and will do that as well. But now I know there is a solution and I have other things to turn to around the house, so it isn't critical. I can do it whenever I feel like puttering around with something.
The truth of the matter is it wasn't that critical to begin with. Unless you were looking right at it or knew where to look, most of the little chips, scratches, scrapes, and door dings were imperceptible. The general condition of the paint is pretty good, but it's a 12-year-old vehicle and there is normal wear and tear just from it being driven. For the time being, I can get away with a little touch up paint here and there. My sense is that general state of the paint is going to deteriorate over time to the point that it's just fair. I'll cross that bridge when I get to it (to paint or not to paint, that is the question). Right now, I'm happy with it.