Dead Stop vs Touch And Go Deadlifts

This is a subject that you'll see debated on forums all the internet. People will argue one way is the best and the other way is useless. The reality is they are just different. People have become big and strong using both methods.

 Advantages & Disadvantage of the Dead Stop Deadlifts

• Advantage: As you're lifting from a dead stop, it works your speed off the floor better than touch and go deadlifts. 
• Advantage: As you'll have to reset for each rep, it gives you more chances to practice and perfect your set up technique.
• Advantage: Each rep will be more consistent. With touch and go deadlifts you might get more assistance off the floor with some reps than others.
• Advantage: It's sport-specific if you're a powerlifter.
• Disadvantage: Less time under tension.
• Disadvantage: Doesn't work your grip as well.

Advantages & Disadvantages of the Touch and Go Deadlift

•  Advantage: It's an overload technique. You'll be able to perform more reps with the weight compared to dead start deadlifts because of the stretch reflex aids at the bottom of the lift.
• Advantage: There is an increased time under tension as the muscles are under load for the whole rep as you need to control the weight on the way down.
• Advantage:  It's better for grip strength. With touch and go deadlifts you'll be holding a heavy weight in your hands for a long time. High rep trap bar deadlift massively improved my grip strength. 
• Advantage: Easier to stay tight which can reduce the chance of injury. As long as you don't bounce the weight of the floor, touch and go deadlifts forces you to use a very controlled eccentric, so you stay tight for the whole rep. However, if you divebomb the eccentric, don't place the bar in the right place and bounce the bar off the ground you greatly increase the chances of being injured.
• Disadvantage: As you use the stretch relax to help aid you at the bottom, it doesn't train the speed off the floor as well.
• Disadvantage: You only get to practice the starting position on the first rep. If you were competing in powerlifting you might want to practice the set up more often.
• Disadvantage: As you'll be able to do more reps compared to dead stop deadlifts, if you put your touch and go deadlift into a  rep max calculator, it will greatly overestimate what you can do for one rep.

In general, I recommend that most people reset in between sets but do them with a controlled eccentric and only a brief pause. All my clients lift from a dead stop. I would only ask someone to do touch and go deadlifts once they were experienced and their technique was good.
Most people will end up cheating with touch and go deadlifts, especially when they're fatigued and end up bouncing the weight up. 
I like to do touch and go if I'm doing high reps on a program like 5/3/1, and deadstops for low reps, and I've made my best progress when doing touch and go deadlifts.