Atma

Sometimes, it's difficult to get stuff done in a PP/OP. With a SP, you set your own speed, goals, and such. Both have their advantages, but each individual has their reasonings.

I play a few SP's there slow but they allow you to control all the things in it.

Personally, I prefer a Private party and sometimes open parties. However, I'd said a solo party is fine too. It lets you keep yourself occupied with the site when no one is responding or something like that or don't want to wait on wait times. I suppose it's an acquired taste I suppose.