I'd also like to point out that the number one most successful LONG TERM diet to keep the pounds off is Weight Watchers, which is a simplistic calorie counting approach offering protein, carbs, and fat... where Atkins (ketosis) is quite farther down the list. Even Atkins, which was originally 100% carb free, has now incorporated small amounts of carbs.
In my opinion, it's the fastest way to shred some fat, but that fat will come back quickly when you re-introduce carbs (in comparison to other diets), and it's very stressful to your body especially if you're lifting. I would take a Paleo diet long before a keto diet

I can't do that one either though, because its much harder for me to plan out all my meals, since most of mine use whole grains as carbs.
However... if you want to try Keto (to each their own), I would definitely not stay on it for more than 3-4 weeks tops, and then SLOWLY re-introduce your carbs. I've tried it once, and I felt awful. I couldn't do it for more than two weeks. Replacing carbs with HEALTHY fats is very difficult, even though fat has a tad more than twice as many calories per gram. And you have to remember too, that even though it keeps your insulin levels extremely low, you can still store fat if you overeat.