I scraped in my saddle and tailstock on the 7x14 lathe I started with. It made a huge difference. Initial contact on between the saddle and the ways was on 3 points no more than 1/4" diameter. That being said, it wasn't a quick process. I have heard of others lapping their ways. Some came out ahead, some came out behind. If you want to see how bad things are, it is fairly cheep to check the contact surfaces. Purchase some bearing blue (enco carries it). Pull off your carriage/mill table, and apply a (very) thin coat of glue to one side, then place the other side back in place with the gibs loose or removed. Apply mild, even, pressure and slide the part back and forth about 1/2" inch about 3 times. Then remove the table/carraige again and look at the two surfaces. On the part that was clean initially, there will be blue spots where it was contacting the mating side. On the part that was blued going in, the blue will be gone, or lighter than the surrounding area. The ideal case is for even spots of blue across the whole surface. If you only see blue in a couple places... well, lapping or scraping may help you. If you decide to lap, proceed with caution. If it were me, I would use the silicon carbide paper rather than the clover paste. Go slow, and measure often.
A lot of people (when starting out) think that ways should be mirror flat and shiny, but that is not the case. It's actually the opposite of what you want. If the mating surfaces are too flat they squeeze out all the lubricant, and then you have dry contact between the two, which leads to premature wear. This is why scraping is still the preferred method for machines. Some manufactures try to get away with a middle ground (hahah), so they grind the ways, and then "flake" them. This produces small, irregular surface imperfections that act a lot like a fully scraped surface.
That was a bit more long winded than I had intended... but there you go.