First "bothers" is not quite the right expression, it should not
bother me that you seem happy with your solution. It was accidental I noticed the thread but the mention of any Hewlett Packard printer always gets my attention if I see it.
The mention that you could not get the PostScript driver to work, was a red light to me. I am not 100% sure that the 5P is dedicated PostScript printer but I thought so, my memory fails me. Postscript should have been the simplest and that stuck in my head.
If you are perfectly happy with what your printer is now doing for you leave it at that. There is a general postscript testpage at /usr/share/printer-testpages/testpage.ps
you could open that in Okular and print it out if that looks fine, foomatic driver doing ok.