Quote: I'm more the highpoly-guy ^^
That's okay, but 603 tris isn't highpoly - its a mid-poly (in relation to the size of the object) that can't really be used for anything. Its not detailled enough to serve as a normal map bake and has too many polys for a proper lowpoly. Well...okay since this is such a tiny object it could maybe be used for a bake...but you know what I mean!
So if you want to make highpoly make it HIGHpoly. Ram up the turbo smooth. Throw all details in there that you can think of. Sculpt it, if you have the program for it and it makes sense. And then when you make the lowpoly, make it LOW. Throw out every triangle that you don't absolutely need. It takes some practise, but after a while you'll know what kind of details need polygons and what can be just as well depicted by the normal map.
In any case, don't float around in the middle. High or Low - but nothing inbetween
(Well, unless its a basemesh... aaaaaah stop, stop, I'm rambling again >.<)