Here is a good read by Chuck Hawks comparing two nearly identical cartridges. It explains the technical differences in a way that does not make one feel stupid. In other words, it is in plain language.
Full article here ---> http://www.chuckhawks.com/compared_243_6mmCreedmor.html
The bottom line for me, though it was not specifically pointed out in the article, is that if you are going to invest in a PRS rifle for competition, go with 6mm Lapua if you are really looking to eek out that extra .01 moa. Otherwise, just get a .243. All the 6mm CM, or Lapua for that matter, does is allow the reloader to seat a longer (and heavier) VLD bullet in a case with a slightly shorter neck. For the average non-competitor who will be happy with .5 to 1 moa, 243 makes the most sense as the rifles and ammo are far more cost effective. For example, a .243 Ruger American Predator Rifle will cost about 1/3 that of an entry level 6mm CM and off the shelf ammo is half the cost. If you absolutely have to have .25 moa and reload (as most competitors do) and have a trust fund to bankroll your hobby, Creedmoor (or Lapua) all the way.
DT made a comment about not spending that size cash on a GM. For four times the dough it better be better looking. I’d agree it’s tough to beat the looks of the Ferrari, but hasn’t that almost always been True? The 488 looks fantastic. It’s all about personal taste in the end. From your avatar you’re obviously a ford guy.