I wouldn't say ditch your drinking buddies. Well for me my buddies felt like I ditched them because my gf always wanted me to spend time with her. I would come back from work, tired always busy with something else I need to do at home so it was either I hang out with the woman or go with my buddies to some bar in the middle of the week and then have to go to work like crap.
I did that few times, I have med school friends and friends who are still in school, they go out every tuesday or thursdays for specials. EVERYTIME I went with them I would end up staying later, drinking more, feeling like crap waking up at 6am to go and write code for work. Not a fun time, there were times I felt so bad I had to call out. One night I even got a speeding ticket and I was ....... Thank god I wasnt asked to take a test. I wasn't drunk but you could easily tell by the look of ones eyes, smell, especially if you had lots of hard liquor and a buddy in the passenger seat that won't shut the hell up because he obviously had a good time.
I still hang out with my drinking buddies but its less often and when I do drink I notice that after you have less for a while, you either get a headache because you need to keep drinking when the buzz goes away or you just feel full.
Oh and I have not been able to ditch the e-cig while drinking. I can stay in and drink while my buddies go out for a smoke, but at the end of the night I'm on my e cig.