Mike will deliver what he advertizes and stand behind his product if there is a problem.
Realize gas use goes way up once you start passing 670fps (in .22 / 14.3gr), and the difference a bit more speed makes down range isn't as drastic as you might assume.
IF you start out a .22 CP at 650fps, sight in at 30yards, it will be moving about 500fps at 50yards with about 4.5" of drop.
If everything stays the same, but the pellet launches at 700fps, will end up at 50yards going about 530fps with 3.75" of drop.
3/4" of drop difference isn't a whole lot, neither is 30 fps, and to get it will cost about 1/4 more gas use.