No,
I used 89C51 for a long time before I choose PIC. the fact that PIC is very very difficult to buy in Vietnam, and I have no thing to start with PIC. I don't have teacher, I don't have books...
However, when I use PIC, I found it very strong.
PIC is not a single uC, PIC is a family of which instructions are similar, that is, you can use most types of PIC with great ease if you knew one of them.
For the package, I only discuss bout PDIP, because it's popular for designers. PIC has from 8 pins to 80 pin PDIP chip. And you can use them for different applications.
For 89C51, it has 40 pin with no special functions such as: A2D, Capture, PWM, communications... They only have RXTX communication. 89C51 usually run at 12MHz, and an instruction cycle is 1us. However, PIC can get 10MHz instruction with 40MHz crystal.
For midrange PIC, it's 20MHz crystal (5MHz ic)
Rom and Ram is not the problem.
you shouldn't compare 2 uC by comparing which is faster.
you should compare about:
1) How many people use it, that is, you can have their help
2) how long is it used, that is, how many specific applications are built, and you can take examples from
3) how easily you can learn it? PIC has 35 instruction and 89C51 has hundreds of instructions
4) how easily you can get help from provider? You can have free samples with ease
5) how easily you can program and test your program? Do 89C51 has ICD? and ICSP?
6) Do you have free debugger as MPASM?