The adapter kits are certainly easier and more convenient (I have one on my BJ8) but, to answer your question:
My opinion is the paper is fine, and I believe quite a bit less expensive (most modern spin-in filters use a "paper" element). The felt version will probably filter better--though I have not seen any technical comparisons--but, it may possibly filter TOO good, removing some of the additives in the oil. This was an issue with the old Franz oil filter, which used a roll of toilet paper to filter oil in a bypass-type (non-full-flow) system. I have not seen any evidence of this, just have a suspicion of a possibility.
I'd love to see some actual data on this, but I wouldn't lose any sleep using either. Unless you change your oil a lot and want to save money, I'd use the felt.