It's hard to say how painfree I am. If I try to quantity that allover achy feel that makes it painful to just roll over in bed or walk or bend or move, and give it an "8" rating (with no Lyrica), I would say that 150mg twice a day gets me to a "4". At that level of "4", I'm not thinking about the all over achy feeling. So taking that amount of Lyrica eliminates about half of my fibro pain. I didn't give my untreated pain a "10" because that would mean being totally bedbound by the pain. A level of "8" means very much incapacitated by the pain and having it affect my willingness to move at all.
I think the constipation is the worst side effect, but that's manageable with stool softener (docusate sodium) and magnesium.
At one time while taking Lyrica I was able to lose 50 lbs through dieting, so I think it's possible to take Lyrica and NOT gain weight if you pay attention to what you eat. I find that Lyrica increases my appetite. I think it's important to know that not everyone gains weight while taking Lyrica.
Here's another perspective, with comments from users:
http://mentalhealthdaily.com/2015/02/10/lyrica-weight-gain-what-should-you-expect/