it seems to me one of the issues "P5ers" have with P6 is, that they can never rely on symbols in P6 having the same meaning as in P5.

I don't have a problem with P6 syntax being different to P5; even where those differences are subtle enough to catch me out a few times. The products of evolution -- when enough beneficial mutations have accumulated -- are always new species. They live along side each other without interbreeding for a while, and, if the mutations are truly beneficial, they eventually out compete their progenitors and take over niches wholesale.

In the 10 years since I first became aware of the possibility of P6; I've learnt enough of at least a dozen new languages to try them out on a few sufficiently complex problems that I could compare and contrast their benefits and drawbacks for myself. For the most part, different syntaxes don't bother me too much if they aren't too obscure, are reasonably well documented, and aren't too verbose.

My assessment of the bits of P6 I've seen/picked up are that it would be right up my street; and that the learning curve would definitely be worth the effort for the gains.

My only real problem(*) with P6 itself is that for most of the things I do, it simply isn't fast enough. I quite frequently will wait many hours or days for a P5 program to complete -- when I know full well that written in C, or D, or C++ or Java, it would perhaps take 1/2 the time or less -- because I know that it would probably take me longer, than the P5 code takes to run, to write the program in those other languages. That's what keeps me using P5 for the majority of my code.

But to have to wait a month for P6 to do what p5 does in 2 or 3 days is too much; the gains from the new syntax simply aren't enough to justify it.

(*)The other problem is the hyperbole and broken promises...