The Energon Pub

Does anyone have experience (good or bad) using Gundam markers?

Would anyone reccomend them for customizing, or are they a waste of cash?

I've used them and liked them.
That was on a Gundam kit though, which is what they're made for. Your mileage may vary with other surfaces.
They're pretty easy to use.
I didn't use any sort of clear protective paint or spray over them, so if I handle the figure too much they tend to rub off a bit. Especially in areas where I applied them fairly thickly.

I would recommend them for small to medium size details, they work well on transformers