For MER, the planetary scientists complained bitterly about being excluded from interesting landing sites by the engineers and mission planners. The managers were so afraid of augering-in that good science got second best. MER went for about $400 million each and had a flight proven EDL system. MSL will probably cost about a billion dollars for a single vehicle with a dodgy EDL system. The problem concerning site selection will be much worse with MSL. With a mass produced MER approach, the managers could take an unorthodox mission tactic. The managers could tell the mission planners that at least 25% of the MERs are expected to auger-in. If there was a higher surivial rate then the mission planners would be scolded for being too conservative. If the program had a total of 12 landers, then 8 could auger-in leaving 4 landers at extremely interesting sites. So the options are;

1) At least 4 MER type landers functioning at very interesting landing sites.
--OR--
2) A billion dollar pile of scrap metal augered into an uninteresting landing site.

Seems like a real easy choice to me.

Tary