I've tried adderal and ritalin and both made it much harder to ejaculate. I remember that it reduced the feeling in my penis. It doesnt mix well with any other drugs so don't smoke weed or drink alcohol if you take amphetamine salts
As for PE, it may make edging easier but you should be careful to avoid injury and overworking your junk.
Started 2/2/12. Data in cm (Change last month) Got back into PE May
BPEL: 17 -> 20.25 (+.25) NBPEL: 16 -> 19.75 (+.25)
MEG: 15 -> 16.75 (+.25) HEG: 14 -> 16.25 BEG: 16.5 -> 18.5
From 6.7x5.9 -> 8x6.6
From ~275ml -> ~410ml = ~49% volume gain in a year and 4 months! 6% last month!