We purchased a "Performer" for Fathers Day and I've spent the last month learning how to cook on it. I've had a Weber Kettle for years, so I've had a bit of experience with cooking on one, but the "Performer" cooks a bit hotter than what I'm used to.
Things and techniques you need to learn with a "Performer"
1. The bottom vent control handles heat, however there is not much movement required from fully open to fully closed. Maybe about 1/2" in the 6" movement of the control. It's something you really have to play with.
2. Get a remote "Grill" thermometer and set the probe directly at grill level. The thermometer in the lid is nice but doesn't give an accurate grill temperature. There is sometimes a 100 degree difference between the cooking chamber and the grill temps.
3. Experiment with different charcoals. I use hardwood lump charcoal for steaks, burgers, etc. I use briquettes for anything that needs to cook longer or for indirect cooking.
4. Learn to build a 2 or 3 level fire. For a 3 level divide the coal grate into thirds from side to side, stack coals 2 deep on the first third, 1 deep on the middle third, and nothing on the last side. As your food cooks you can move from hotter to hot to warmer. It also helps you control foods that burn easily. I use the hottest area for searing a steak and then move it to the other areas to cook or stay warm. You'll find the easiest way to set this up is to use a charcoal chimney, which works great with the "Performer" ignition system. You can distribute the coals without burning your arm up.
5. For indirect cooking use the baskets that came with the grill. You will however want to experiment with the amount of charcoal you use in each. If you use the same amount that you would for a direct cook, your temperatures will still be the same. Again the key words here are experiment. Different brands of charcoal burn at different temperatures. I use Kingsford, not because it's a brand name, but because it's consistent, and it takes one more variable out of the situation.
If you decide to purchase a chimney, I would recommend the Weber, it's larger and holds more charcoal. I would also recommend purchasing another coal grate, that you set on top of the other, but at a 90 degree angle. It solves the charcoal drop thru problem, especially with lump charcoal. When you are at the store to buy the grate also pick up a set of Weber Charcoal Rails. They serve the same purpose as the coal baskets, but it gives you a larger area to place charcoal in, so you can spread the heat out a bit more. Also if you haven't figured it out yet Weber's large drip pans are made to perfectly fit between the baskets and rails when you indirect cook.