With blocks, you have to raise the car and crawl under to get the blocks in, then lower onto the blocks, raise & crawl again to get the blocks out, then you have to repeat the rigmarole for each of the 4 heights.
I have an alloy measuring stick that stands on the floor with the wheel centre marked and each height to the wheel arch marked. True you have to go round a couple of times for each height as adjusting one corner affects all the others but with the RSW software it's a pretty quick job with no crawling.