When I used MX-S and MX-P and OVA Tenergy 05, I found that OVA and MX-S and MX-P in 1.9-2.0 approximated Tenergy 05 in 2.1 weight wise and that there was really nothing I lost unless I Was loopdriving 20 feet off the table. So I have stayed with 1.9mm for the hardest ESN sponges since then...