ASP comes off easily 5-10 mins, its like cuccio.
I'd say to buy yourself the base coat (its different formula so you need it), a colour you like and a bottle of the top coat and try it. Top coat is optional but makes it more hard wearing. Try the glitterise for a nice sparkle or disco ball. It has 3 levels of glitter and a mother of pearl I use as special effects over the other colours, plus you can mix them on a piece of foil or dappen dish to make custom colours.
It's not a high end product but has some lovely colours and is easy enough to work with if your good with a brush.