Been there, done that a couple times.
I have concluded it doesn't provide any increase in euphoria, rather, possibly the opposite - mainly an uncomfortable awareness of my heartbeat as well as increased sweating, core body temperature, anxiety, blood pressure, nervousness, etc. Basically, from what I've experienced first hand, it'll make you feel like a cross between tweaking on some very poor quality methamphetamine and consuming a shitload of caffeine. I found it to be dysphoric and I had to resort to popping a few Xanax to dull the aforementioned dysphoria, which, also ended up dulling the mdma.
Ephedrine - I find - is useful for 6 things mainly:
1) Helping you stay awake when caffeine won't.
2) Reversing sedation induced by benzodiazepines, barbiturates, z-drugs, anticholergenics, antihistamines and so forth but not ethanol.
3) Reversing certain causes of hypotension and/or vasodilation in some cases.
4) Combining it with caffeine and aspirin (ECA Stack) as a diet pill.
5) Using it in therapeutic amounts (e.g. 8mg q4-8h) as a nasal decongestant.
6) It's a precursor to methamphetamine (not that I'm condoning methamphetamine use - just saying).
