On a RGB strip the 3528 strings,each led is its own color; unlike the 5050 all 3 colors are on one led. Also because the leds are seperate the leds are smaller on the 3528. The 5050 seems to me to be just a little brighter than the 3528's. Both strands seem to be the same 1m-5m in length, but i cant see how the two strips could have the same led count.