I can certainly tell you this:   if you have been using Perl “for more than 4 years,” then you will probably do better if you can just find a way to explain what you did, and what might be the business value of that experience to a future employer.   (Never mind the recruiters... what do they know, anyway?)   This is a craft that you learn by doing.   Therefore, my number-one and number-two questions would be:   “what did you do?” and, “show me your code.”

A certification is ... a product.   It is a product that is sold to people like you.   An affirmation, if you will.   A pat on the back.   An attaboy.   A feeling of accomplishment, of having successfully crossed the finish-line.   But, was anybody actually in the grandstands when you did it?   To me, if I were a prospective employer, it does not really tell me anything objectively.   But if I can see your work, and hear you talking about it, and get you into some serious conversation, then I can learn a great deal about you in a few minutes’ time.   Far more than I would ever learn from a piece of vellum with gothic-font writing on it.   And if I am about to make a multi-thousand dollar purchase (of your time and expertise), that matters.

Analogy:   “So you say you’re a ‘certified cabinetmaker.”   Okay, cool.   Whatever.   Do you have some references from recent customers whom I can call?”   If I am about to get into a boat and set sail, I want to talk to former passengers ... not calligraphers.