Remember, I said, "...prior experience is a big plus in favour of a processor..."

so your experience, and all that scope for re-use, will obviously get the 8051 near the top of your list.
However, your experience will also tell you where an 8051 is not a good solution. If you decide to be an 8051 specialist, you will happily turn these jobs down; but you won't be intimidated by them - which was my original point!