TS,
I've been vegan for almost eleven (11) years now and couldn't be happier. First off all, when I went vegan, I dropped 10lbs in about a month. Losing weight wasn't the goal at the time, but a nice/unexpected reward I must say.
Now that I train six days a week, my diet has become a huge part of my daily life. Personally I feel better than I ever did when I ate the typical omnivore (American) diet. I'd say if you're looking to lose weight, going vegan/vegetarian will be able to do the trick, as long as it's done right. This is the same for as if you were to eat meat. Simply going vegan, and eating vegan ice cream, potato chips and soda will not do the trick.
Personally I monitor my intake of just about everything. Right now my current goal is to continue to drop body fat % while gaining lean muscle mass. I've been on a strict diet for the past five weeks and here is what I've attained so far:
Height: 6' 4" (this didn't change, ha)
Weight: 246.8lbs (changed, explain after these stats)
Body Fat: 16.2% (changed, explain after these stats)
Five weeks ago, when I first started, I was:
Weight: 254.7lbs
Body Fat: 22.4%
When weighing myself weekly I noticed I ended up dropping down to 242lbs. So after dropping body fat, and building lean muscle, I've gained some. After three more weeks of this training/diet routine I plan on changing it up to cut some more weight. Eventually I'd like to get to 230lbs and then maybe do another bulking cycle.
In regards to soy, estrogen levels, etc - I wouldn't worry too much. I'll have another physical after this routine but prior to starting this routine, all my blood work came back with normal levels. Also note that my soy protein intake varies day to day but still is higher than your average person. With this routine though, the only soy protein I'm eating is NON-GMO Tofu. Other than that, my protein comes from nuts, grains, etc.
On that note, I don't have "bitch tittie" or anything of that nature.
I'd suggest you simply give it a shot (if it's something you really are thinking about) and see how you feel. My brother went vegan when he was weighing 325lbs and in three months of being vegan he dropped to 279lbs.
Good luck with whichever decision you make.
Oh, on another note - these people saying we have "non-molar" teeth is just a silly reason for believing we should/are meant to eat meat. Just run out to a pasture and jump on cows back and sink your teeth in. See what you get. I'm doubting you'll satisfy your hunger.
Just because we've evolved and developed methods of slaughtering the animals for food doesn't mean it's quality evolution. In fact, a lot of what we've evolved and developed isn't in sync with evolution. If you ask me, we are taking a giant leap backwards with some of the shit we've come up with as humans.
Anyway, good luck!