To me the 5HT agonism of LSD is a lot more euphoric than the 5HT release of MDMA and other SRAs.Exactly that's why I don't understand posters that refers to LSD as very euphoric.
LSD shouldn't interfere with tramadol, as LSD is not a serotonin releasing drug.
I'd advise caution with this. I recently got a pretty nasty case of serotonin syndrome when I took LSD after 100mg of tram (prescribed for pain and rarely used for recreation). Details to be found here (http://www.bluelight.ru/vb/showthread.php?t=362749&page=20#492). I couldn't feel the tram one bit (other than the pain relief) and had no idea that it could interact so seriously with LSD. I avoid tramadol for 24 hours before and after taking LSD now and have had no problem since.