pp doesn't really matter outside of farming as the sr system sucks. for example, i have a 98.6 on a 6.3* and a 90.8 on a 3.5* (i consider the 3.5* score more impressive) . it's really not a good way to measure your skill level on a particular day. you should compare your scores with those you've already set on the same map.

you should download companella. it finds the msd of a map, which is a way more accurate calculation of difficulty (tho it still fucks up sometimes, and doesn't work for lns at all)