I've been vegetarian for 12 years. From what I've seen:
1. Vegan = Poor Health. Unfortunately, every person I've known who went vegan, sees their health decline within 3-6 months. They usually end up swinging entirely the other direction and resume eating meat. It is absurdly hard (maybe impossible) to maintain your health on a diet with no animal products.
2. Vegetarian can be cheaper, but a person's approach to their shopping and cooking is far more critical. I wouldn't go vegetarian just to save money. Especially if someone still tries to eat a healthy diet, protein just costs money. There's no getting around it. IMO, people that insist veg is cheaper are really insisting a low protein diet is cheaper, which is true. You can eat flour and water for pennies a day.
3. If someone eats the nutrionally best diet they can, a diet with some lean meat and fish is healthier than a vegetarian diet. The reality is, the health improvements associated wtih going vegetarian come from people cutting crap from their diet. Also, people that decide to go vegetarian have already decided to think critically about their diet and will eat better than average anyway.
4. I do think eating vegetarian is more ecologically efficient. It makes shopping / storing / preparing food simpler. It results in killing fewer animals.
Ultimately for me, it comes down to the fact that I could milk a cow or take an egg. I couldn't bring myself to slaughter a pig or behead a chicken. I'm not comfortable with outsourcing the activities I'd find so distasteful to someone else. Factory farming makes that especially true.
When possible, I even pay the premium for organic diary / pastured eggs. Again, it comes down to how I'd want my food animals handled. If I were to eat meat, it would need to be "happy" meat.