Up to now, using the subroutine-specific variable names has made it easier for me to keep track of what's happening to which variable at what point in the program.

But at this point I only have a dozen or so subroutines. I see your point - this could get hairy as that number increases. I'll eventually have to keep track of the initials of the subroutine names, to keep the variable prefixes unique. Hoo, boy.