I've read a few of tutorials about setting games ini, mainly ipreloadsizelimit and threads settings, as well as Osr. They are rather old on the other hand so I wanted to ask in 2015 experienced and long time Oblivion players about their settings that they have been using and they think they play the best.

In ini the most notable is ipreloadsizelimit, which I read by Martigen was (few years ago) recommended to set quiet low, about 3x bigger than default for Fcom and few mods in my case. The most recent posts about Oblivion performance I've seen users using large values, few times bigger than mine that take the whole PC ram.

Also OSR critical section seems to be interesting and sometimes changed.
I'm using some newest mod community tools such as Oblivion reloaded purger, moreHeap.

I'd like to see your view on that matter.

I'm not sure there is definitive agreement. I'm using the settings recommended by UESP and/or the ones from the old TESCOSI site that is now in TAL.