From a physiological point of view, there's little question that they are equally effective. Spraying liquid vitamins into your mouth puts them squarely in the digestive tract. Digestion begins in the mouth, in fact, and simply continues in the stomach. So as long as you don't spit out the vitamin sprays, you'll be digesting them just as well as vitamins & minerals you might be swallowing.
The real question, in my opinion, comes down to cost: is the cost per dose worth the price? Without question, liquid vitamins in a spray format are far more expensive per dose than other forms of vitamins such as whole food supplements. I haven't done the math on these, but I wouldn't be surprised if they were twenty times more expensive per dose. And yet, at the same time, all vitamins & minerals are cheap compared to the high cost of medical care that can be prevented by taking supplements, so even high priced sublingual sprays, if they're what you need, are worth every penny.
The key question about these sprayable vitamins, then, is a personal one: is it convenient for you? If the spray format helps you take vitamins & minerals where otherwise you might not, then certainly they're worth the cost. These sprayable vitamins are also convenient for traveling or carrying with you to work. Regular vitamins & minerals are sometimes hard to carry around, but these liquid sprayable vitamins are as convenient to carry as breath freshener. That benefit, all by itself, easily justifies their price.
The bottom line: if you're doing fine on capsules, pills and tablets for your vitamin & mineral supplements, then you may not need liquid sprayable vitamins. But if you enjoy the convenience of being able to easily carry vitamins & minerals to work, on the airplane, in your purse, etc., then by all means consider these sprayable liquid vitamins.
Do I take them myself? No, I don't, but if I were about to go on a trip, or I worked a regular desk job, I'd definitely buy some and use them regularly.