first one is obviously way to empty (wich is why you changed it...)

1)my recommendation is lose the blur around the renders on the third one. renders should either blend nicely or look crisp and smooth...
2) try to get some more bg going on. It just seems a tad empty to me.
3) LOSE the bevel&emboss on the text "rp board". the sooner the better... actually. Try and get some effect going on with your text other than the bevel. I can't stress it enough...
4) they need borders.

yours actually looks better. the text looks pixelated tho. the fire effect is well done. but again, the whole of the sig is too empty. Either add more to the bg -or, and I would try this- make the sig smaller so it's only the text. And also give it a border. sig's will look nicer with border.

keep it up. the ideas are good, just get more practice.

PS: does one of your sigs say "Flurry of dancing knives"?
Should this be "Fury" ? just asking...