It's about as confusing as it can get.
But then go down tesco's. look at the washing powder range. They all claim to be the best. Obviously they all can't be.
Just pick what you can afford. it'll do the job (more or less). Considering what i do with my pc, i think i could still be using the old 66Mhz thing, with 32Mb ram, and win 95, from 8 years ago (assuming it still worked now) and it would be no slower. The only difference? Win95 had no (reliable) usb, so no BB Usb modem..