Why not cast on about 32 sts (make it a multiple of 4) and do some 1x1 rib, then cast on again, same number of sts, same needles, work the 2x2 rib and compare for yourself. If you work a couple inches each, you can see for yourself what the differences are and which you'd want to use where. You might even save the swatches for future reference.
You can't knit the left sock first. Ever.