I have mine set at 60 % fat, 25 % protein and 15 % carbs. I'd rather go over on fat than carb. I switched it down to there a couple weeks ago. I got better results. I find it difficult to get all the fat in for the day.

The primary function of dietary protein is cellular maintenance and protein synthesis, not energy, and thus your protein goal should be based on your lean body mass and level / type of exercise, not a percentage of total calories. My lean body mass is ~160 lbs, and I shoot for 120-160 grams of protein per day. I do high intensity exercise twice a week (1 x HIIT, 1x Weights), and generally have a 30 g protein piece of fish with a little butter or oil immediately after a workout.

Carbs are a personal preference, but should be a fixed range independent of your weight and total calories. I try keep my ketone levels up (above 1.0) and my blood glucose down (under 110) and thus aim for 25-50 g net carbs per day. Depending on your goals you could certainly go up from there, and/or eat some additional carbs after exercise.

After determining your carb and protein goals, fat should then make up the rest of your calories, as it is your primary source of energy. But switching between, say 1200 and 1600 calories shouldn't affect your protein or carbs, you'd just eat more or less fat, and thus use more or less stored fat to make up the difference between what you eat and your TDEE. I know you can't specifically set MFP up like this (yet?), but it's the proper way to think about things, and you can try to massage the percentages to get your MFP goals as close as possible to your true goals.

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Note: If you eat too much protein it will get turned to glucose aka carbs aka sugar. If you eat too little your body will have to break down muscle.

Note: Your red blood cells and brain do need a certain amount of glucose, which is generally taken out of storage from your liver as needed, or synthesized from protein if your liver's glycogen stores are empty. Your muscles can also store a limited amount of glucose for use during exercise. Too much glucose in the blood is poisonous, and thus your body tries to tightly regulate blood glucose levels. Eating carbs causes a release of insulin which tells your liver, muscles, and fat cells to clear the glucose from the blood and store it for later use. The liver and muscles store glucose as glycogen, which can be broken back down into glucose and released to the blood (by the liver) or used for exercise (by muscles). Any glucose stored in fat cells is converted to fat, but fat cannot be converted back to glucose (though it can be used to produce ketones). Eating more carbs than you burn will keep your liver and muscle storage topped off, and thus result in increased fat storage. Eating too many fast acting carbs at once will cause your blood sugar to spike, and thus result in increased fat storage as your body tries to clear glucose as quickly as possible.

Mine is derived from a few sources: The Primal Blueprint, tips from other primal/paleo eaters, and a few other random sources I can't quite recall at the moment. It's also been working for me quite well so I haven't felt the need to tweak it further.

My macronutrients are currently set to:
Carbohydrates (20%)
Protein (25%)
Fats (55%)

I agree with Smooth--that's exactly how I calculate my macros as well.

I eat 1g protein per pound of lean body mass. I stay around 60g carbohydrate/day, and the rest is fat. I don't stress out about going over slightly in any of the categories including carbs (I'm not afraid of them, LOL), so long as I am hitting my protein goal. The actual macro breakdown for me has worked out to 30% protein/15% carbs/ 55% fat.

I lift heavy weights 3 x per week and sprint here and there. On the other two or three days, I train with kettlebells doing vo2 max workouts. I also walk a lot, as that is my main mode of transportation. My objective is to lose fat and maintain as much of my lean body mass as possible, hence the protein.

I've found that if I eat higher fat/lower protein/low carb, I feel sluggish and can't progress my strength.

try and keep carbs to 50g and under per day. for me its 15%, 65% fats, 20% Protein. Adjust Sugar to 25g. Lower Sodium by 700g. That should get you on the right track. To reduce the sugar load I have 1 piece of fruit a day usually right when I get up or with my first meal of the day. The rest of the day I have vegetables combined with meat.