it's comparing apples and oranges. PICs are microcontrollers, PEELs are programmable logic devices. the differences between microcontrollers and PLD/FPGA/CPLD/etc has been discussed before on this forum, I'm sure you can find something.
Microcontrollers execute a program, PLD's implement a logic design. I think it should be relatively self-evident which one would be more suitable for a given application. In many cases, either one would be suitable, however PLD's are far less common among hobbyists. Writing a program is often much simpler than coming up with a complex logic design to do the same thing, especially if you would have to implement a bunch of sequential logic to do so. PLD's seem to be more suitable where you are dealing with a lot of I/O, particularly at high speeds and/or where you need to do a lot of things in parallel.