I run a small development company doing embedded designs. I have used PIC's, 8051/2's and AVR's. I find and develop with a processor that best fits the task at hand. The real comparison is usually between AVR and PIC. As soon as I'm doing a project that involves data logging and that type of stuff I will use a 8051. They are the easiest when it comes to adding lots of memory and you don't pay for all the peripherals you are not going to use. If I need a lot of peripherals like ADC, PWM and I need a fast execution time and space is a problem and so is power consumption, then I look between the PIC and the AVR for which one has the bit's and pieces I'm looking for and my decision is based on that.