Any idea what can be influencing rtMedia to give such bad performance results? See screenshots. 65%… multiple tests keep giving rtMedia bad perf results. Might be conflicting with another plugin?
I know this is not an easy question and a difficult matter to troubleshoot…
Thanks
Giorgos
P3 Performance Profile is an EXCELLENT plugin if you are bad at statistical math. 
Why?
It doesnt give you any useful data.
All it shows you is that out of all the things your page needed to load, rtMedia too up about 70% of those resource loading times. And then it puts it in a fancy pie chart so you think you can see what plugins are “hurting” you performance-wise. Very useless! 
What it does not do, is tell you a pie chart of what percentage of the page requires a plugin and then show performance data vs that chart. Look at all the other plugins you have – they all do basically nothing. rtMedia has a lot of things to lookup, load, and then display, that’s why the numbers are high.
If you disabled rtMedia, all of a sudden your pie chart would show BuddyPress as taking up 40% of the pie chart. Does that mean buddypress is slow? Nope!
If you want to test performance, test load times. ( tools.pingdom.com/fpt/ ). Or, better yet, install “Query Monitor” plugin from the free wordpress repository. That will tell you what SQL queries are slow.
You’ll probably be amazed, that rtMedia is a very fast and well optimized plugin. I run it on a site with over 60,000 members that has over 130,000 videos and pictures. Fast as all hell.
I’m not a rtcamp employee, just a guy who uses a number of the plugins here. You should safely uninstall P3, it’s just useless garbage.
Ben
Thanks for your response Ben. I got your point. Indeed when I disable rtmedia, WSI plugin becomes the bad one. I already install Query monitor as per your advice.
P3 disabled, for the moment
Thanks @illusionsglass for your helpful reply and @giorgos for your understanding + testing.
There are many areas where WordPress performance can be improved.
I just published our internal checklist here - https://rtcamp.com/tutorials/wordpress/performance-optimization/