What you are seeing is the PAR decompressing to a temporary directory. PAR leaves files in a specified temp directory to speed successive executions of the same package.

I use PAR and PerlApp with great success. Each has its strong points. PerlApp has somewhat faster startup times and a smaller memory footprint. PAR generates smaller binaries and it is easy to look inside a package.

Even if you use PerlApp you will still have some lag at startup and a short period where CPU utilization peaks while perlapp decodes its proprietary format.

P.S. Here's an example of what I mean when I say perlapp starts up faster. I have a ptk app that makes a perlapp binary that weighs in at 3.8 MB. The equivalent PAR file is 2.8 MB on disk. In memory, perlapp takes 18.8 MB, PAR takes 22.3 MB. When I start both apps at the same time (second run for each) the PAR loads about 1.5 seconds after the perlapp file. YMMV