Lee, Lyman, RCBS are all reasonably good quality molds but certainly nothing special. The biggest quality issue with all of these is that some of them throw bullets that are just slightly smaller than optimal diameter. The cherries (tool used to cut the mold) wear with use and make smaller cavities as they wear down. These makers will keep using the cherries past their optimal size with the result that the cavities they cut are smaller than they should be. If you get a mold than has been cut with a fresh cherry then it will be fine but if you are unlucky enough to get a mold that was cut with an old cherry then you SOL. You can size a bullet down, but it's really hard to size it up.
For better quality molds you need to move up a notch to MP Molds, Accurate Molds, NOE Molds.
They are head and shoulders better quality then any RCBS, Lyman. or Lee.