I don't think that perl is a source of bugs or problems... why would any other client use it if it was?
perl5 is quite stable, there are libs to include it quite fast and easy...
maybe mIRC language is fine to you...
but... I'm used to quite powerfull and mature languages (such as perl5 and c++) and to me... mIRC-script is THE source of bugs and problems...
further...
to me mIRC-script would be the third language I use regularly (counting c and c++ as 1)... and that's quite some stuff to remember... e.g. no $var in c++/c, $var in perl and %var in mIRC... and that's just the tiny top of the iceberg...

so long