I havn't used Tcl/Tk. Since Perl/Tk is derived from Tcl/Tk, I would assume that they are quite similar, except for the Tcl syntax. There is an ongoing argument going on in comp.lang.perl.tk about whether the Perl/Tk is better than Tcl/Tk, the argument being that Tcl is the original source, so there are bound to be glitches in the conversion. The response of course, is that Perl/Tk is better because it's Perl, not Tcl. :-)

The releases of Perl/Tk always lag behind the latest release of Tcl/Tk. I think that Tcl already at the 8.5 level(still classified as devel), where Perl/Tk is still at 8.4

Nick and Slaven are always lurking in comp.lang.perl.tk but they are selective in what questions they answer, leaving most simpler stuff to others to answer. They are there.