Gurobi is a MIP solver right, not a planner? I use Gurobi at work for a certain kind of bi-level programming and it's amazing, like literally ~500x faster than CBC. Picat's planner is more like a Prolog flavor of PDDL (e.g. fast-downward and its ilk.)
MIP, LP, Nonlinear for GUROBI. GUROBI and CPLEX can do planning of course if you formulate your problem in a certain way, but some solvers like Hexaly show large performance gains for things like vehicle routing vs GUROBI as they take a very different approach (don't use LP or MIP).
