Which one is the best solver for solving large-sized problems in Linear Programming, CPLEX or Gurobi? Which one is faster?
I think the performance for different solvers depends on your problems structure. Maybe some of specific problems will lead better performance for that solver.
In general, in my opinion, both of them not far away.
So, if you would like to choose one of them be your solver to solve problem, you can depends on your modelling skills. For example, if you are good at python, I would recommend you choose gurobi, since that have big community discuss some technical issues.