I was a little disappointed after playing the Campaign, then messing around in VS/MP. Campaign was decent, with the Declassified side missions, which really didn't change much, either had to finish within a time period, use specific weapons.. so on. MP, sadly no grubs unless your the playing the new upgraded horde mode. Grenades stick from a distance.. thus being in a sense sticky grenades.
In short, its worth a rent.. those that have been playing since 1 probably won't like it.. but rent it try, you may, may not.