Tobacco

So, i'm gonna quit smoking, what changes should I expect both in the daily life and in my gains?

probably better gains since nicotine is a hunger-suppressant, and without it you will be hungrier = eat more = more gains, in your daily life you probably will feel like shit for a few days

I don't know about gains, since I started working out after I quit. One thing I can tell you, though, is that literally everything in your life will be better after you quit. Everything. Just do it cold turkey so you don't procrastinate and keep smoking like 1-2 cigs per day after almost making it.

Cravings for cigs will be normal for quite a bit, not around the clock but here and there.
You'll taste much more and it won't be all positive. You'll be able to breathe much better but it's a long recovery. Circulation will be vastly improved after a couple of months.

%11 of quitters experience IBS like symptoms after they quit. I know cause I had them. But they went away after 1.5 months

You'll feel sluggish and like shit, you won't be getting anything done, you'll lower your test. It's not worth quitting.

lol ok...

Former chainsmoker here, quit 8 months ago.

Pros: healthier appetite, increased cardiovascular condition, better breath, easier to get up in the morning

Cons: none.

Go for it user!

More weight, mostly fat.
More stamina/longer breath.
Probably fatigue and worse mood short term.

More weight? Never understood why people stuff themselves instead of having a glass of water of a piece of chewing gum when they feel a craving.