Hey John,
I too have burned through LS rubber in about 6 months on 2 different pairs. I have been using LS shoes exclusively for about 12 years, and it does seem that the previous generations of rubber did last longer. However, (lack of) softness (stickyness) was the general complaint about the old LS rubber. A decade ago many people resoled their Muiras with Stealth ASAP. It seems that LS has come around to soft rubber, maybe a bit too far.