This seems more of a TravelBuzz question, but it is here so I'll bite.

I like the free internet where it is available, but that isn't everywhere. CO and NW offer it in the USA. I don't believe any of the other domestic carriers do.

Free drinks from CO/DL/NW are nice if you want to have a couple drinks. I don't think that they have to be rare or special to make up for the $7/pint cost that you'll pay at an airport bar. If you plan on drinking a lot that will add up in a hurry. Drinks aren't of any value for US/UA/AA since they charge.

I will almost always go in to a lounge to make a business call if I have access. Instead of random announcements cluttering the background of the conversation you'll have a relatively quiet space to make the call from. I still use my cell phone rather than the phones they provide just about every time, but I do like using their space.

I've used the showers in a few lounges over the years and generally enjoy them.

Access to the agents is generally the best benefit, but also one that you hope to use the least.

Which PP membership do you get? If it is the one where you pay per entry anyways you'll probably have a hard time recouping the cost of the fee. If entry is just included in your membership then what does it hurt to go in and decide if you get value from it or not?