Well based on my observations which are also also just my personal subjective opinions. I used to do coke for about 5 years, and meth for the last 3. Very recently tried ok coke again and therefore have fresh comparative opinion of both.
1. Coke, due to its shorter duration can cause much more fiendish erratic and risky behavior during the short period of its use and near the end, due to its short duration and (usually) lower quality. For example I remember many nights of running out and dangerous intoxicated trips to resupply in the middle of the night.
This never occurred with meth due to one G lasting at least 4 days for one person as apposed to 4 hours for a average G of coke, and for me at least by the end of meth I am so destroyed, very very over it and paranoid, ive never once gone to get more, i just want to hide away and die.
2. On the surface coke can seem stronger and meth less so, however coke can initially feel thus because the physical natural stimulation feels far more pronounced. Meth however starts off with very little physical sensation but is far more euphoric then coke, even if the peripheral signs you might use to gauge this euphoria may seem less with coke then meth.
Its often difficult to gauge or compare euphoria or the subtle good stuff directly and often we cant help measuring this indirectly through other factors. Hell for a while i used pupil dilation to tell me how high I was, even with years of experience in using both.
3. Lastly coke feels like a far more social "goofy" high with an increased likelihood of the user acting out of character then a stable experienced meth user since meth feels more stable, controllable and "accommodating" of regular human activities, for lack of a better description.
For example, I have lived with very close attentive family and friends (who know I have used before) and it was relatively easy to use meth for 4 day high dose binges at a time for over a year without hardly any suspicion, however I feel I cannot do the same with coke at all. For some reason it feels like I am not in total control with it, unlike meth.
To sum it up, because of the above, I feel that coke may seem more addictive to an external observer on a day to day basis due to the erratic and fiendish behavior exhibited by users on a daily or even hourly basis, largely attributed to the unavoidable mental roller coaster experienced by users due to the short duration of effect and activities/risks related to continued re-dosing (which was my largest issue with the stuff), and lastly the more goofy confident behavior it can cause.
Comparatively, a meth user may seem far more stable and "normal" on a daily basis with aberrant behavior in a weekly or monthly basis. Most importantly the longer term is more likely to reveal a real meth addict as they could be more likely to get away with it longer then a coke addict however regular or daily use will always show eventually no matter how careful or "responsible" the user is with their use.
Personally I would say both are equally addictive with a very different type of addictive behaviors and related symptoms. In the end i would prob say meth was worse, addiction and health wise due to its scientifically proved potency over coke and its longer duration. For me at least I found it far easier to do more, risk more, and get deeper down the rabbit hole with much lower chance of being noticed or discovered.
Also coke could never become more then a social thing for me but meth can easily become so much more then that. Being able to cross that line into "real life" is probably its most dangerous attribute of all.
