Seriously all the pills you have seen are are usually a combination of a multi vitamin and some "secret" proprietary mix which is usually L-carnitine ginseng caffeine and other stimulants. Which is what most energy pills were to begin with. Believe it or not but regular coffee has been proven to have other substances in it other than caffeine to make you alert and its effects are on par or superior to a large market share of energy pills. Just watch the sugar.
As far as the Xzing is concerned I would have to use it to see for myself. It has in each capsule a lot of natural stimulants and energy boosters but the amount in each pill even in a pony tablet has to be negligible. Be advised in most supplements that use raw herbal ingredients that the active ingredients in the herbs can vary wildly bottle to bottle or even pill to pill. So taking more pills than recommended on the bottle to get an effective amount of those herbs can be dangerous.
As the above post notes, energy supplements are tricky. Yes, they do supply energy, usually, but how much and how well depends on you and the quality of the product. This product is really not an energy supplement alone, however; it's actually a theoretical testosterone enhancer mixed with caffeine containing herbs, such as guarana, and other energizers that act on the adrenals. Does guarana work? Yes, better than coffee, but whenever you get energy by taking a stimulant, you crash later, so it's only temporary energy, just like coffee, which is why people drink coffee all day long. It wears off quickly and you crash. But most of the herbs in this, such as damiana, tribulus, etc. are herbs used to enhance testosterone and sexuality. If you're low on this, it might make you more stimulated, but if you take it too often, you can become overly yang, in Chinese terms. It also contains phenylalanine, which is the precursor to norepinephrine, or adrenaline. This combo would make an anxious person anxious. If you're a heavy body builder or athlete, and use this for a burst so you can work out longer, it isn't healthy, but it would work assuming the company is reputable (I wouldn't buy anything from an on-line direct marketer; I prefer up front companies that are willing to face store buyers and their personal judgment about whether they want to sell a product like this or not and who can explain its upsides and downsides to the customer, and I don't mean GNC). Long term this will burn you out. If you want to boost energy on a regular basis, I'd try what are called super foods. They work only because they have superior nutrient quality packed in a small space, such as bee pollen, royal jelly, spirulina, wheat grass, and the like. Super green foods such as spirulina and wheat grass are good in addition because of their high chlorophyll content, which the body identifies as hemoglobin and energizes the blood, and high B12 content. As for the acai berry, it's just a berry, folks. People are claiming this does everything, but it's, again, just a very nutritious berry. In sum, yeah, this combo might give you energy, it's packed with yang nutrients, but if you take it regularly it will end up having a burn out effect, and I don't trust this company to buy quality ingredients.
Personally, I used some vitamins from Centrum that were called Energy. They didn't immediately work (it took about two weeks), but I noticed a very big difference in energy and alertness.