I wanted the MSA Sordins but the price put me off last April. My choice was the Peltor Tactcial Pro (also NRR 18), which is now selling for $234 from MidwayUSA. I added a set of gel seals for $40 from Marv Golden Pilot Supplies, and I'm very happy with the results. So, that's a total of $274, and I believe that the MSA Supreme Pro is almost exactly the same price with the gel seals...the price of the Peltors went up about $35. Oh well.
Can't really tell you how the NRR compares and if a higher number is critical, but I do know that the gel seals make a huge difference in comfort and seem to help with sound level. I use these as an RO with Open shooters, and have no problems (other than trying to keep up with them as they blaze through the stages..). I would qualify that by saying that I only use these outdoors with pistol shooters, and not at the rifle range.