It definantly slows the visions down, although i get transported more so it doesnt always seem slower(slower to take effect a little). It lasts about 45 minutes then a 10-15 minute come down. Rue definantly adds its own twist to the experience.
If you brew 3-5 grams of tea and drink, then smoke about an hour later, all you really need is 1 good hit of changa and wait a minute or two and then lay down and enjoy the ride.
If 1 hit doesnt get you where you want to be take another....i made the mistake my first time of smoking changa until i felt the buzz....i was paralyzed for about half an hour and it was slightly unpleasant for a few minutes.
As far as intensity, it's changa....but deeper
Intensity varys from person to person.
For me personally, i'm not a big fan of the rue feel, I prefer the bliss of caapi
Good luck
and report back