Best and easy are relative terms. Some people like it and some don't. My only reason for installing it was to simulate a particular peripheral.
koolguy, Yes, there are big differences between 8.87 and MPLAB X. The differences are described in much more detail on the Microchip site. MPLAB X is totally new software and has a very different feel to it. It is supposed to be more C friendly than the earlier versions. For someone using Assembly, like me, it allows simulation of some peripherals that the earlier MPLAB SIM didn't do, or didn't do on some chips.
MPLab 8.xx is nice, but Microchip discontinued support of it, and it cannot simulate some functions on the newer chips. I prefer it to MPLab X, but one may not have a choice.