Mishko, you my friend, get a gold star, for asking the best question of the week! Protein is the FOUNDATION of everything we are striving to do in bodybuilding. Everything else is extra. The gear we use is mainly a way to better direct our protien. The training we do is to better utilize our protein. So obviously, quality protein sources are SO very important for maing the gains we want. Our diets require us to eat huge amounts of it. Most of it should be solid food but there is certainly a place for shakes. Whey iso digests much better than cheaper whey concentrate, which is found in most of the "blended" whey products. You will get more use out of Iso, and experience less digestive issues like gas and bloating.  So yes, in short, like you noticed, you will be tighter and drier looking. 

So, first off, YES, I suggest that all of my clients use a high quality whey protein isolate. There are some good brands and some not so good ones too. Some companies have recently been caught "protein spiking". That is, they add cheap aminos to their proteins so that it tests higher. They may claim that a scoop is 24g but in some cases, these companies tested out at 10g or 8g per scoop. It's disgusting that the supp companies would try to take advantage of us like this!!! Truely an outrage. When you look at the label, the ingredients should be very minimal. It should list Whey protein isolate, then some flavoring and coloring. If you see a long list of amino acids like Taurine, don't buy it! 

There is a reason these companies do this. Many poeple don't know it, but there is a very small profit in selling whey. In many cases, companies lose money selling whey but they sell it to offer a compete line of supps and hopefully make up for the loss, through the sales of other products. Fat burners and preworkouts have a much better profit. This is why there are companies that have cut corners.  

Here are a couple companies that I trust :

 Number one for quality and cost in my book is truenutrition.com Dante, the owner, is a good man, who is out there selling a great product for a wholesale price. They have a ton of unique flavors and mix your order by the pound. They have also produced products for other top name supp companies. It takes a little longer to get it shipped, than it would be to go through your normal internet store, but it is worth a few days. So plan ahead and order a little early.

Next, I would look at companies like Divine Nutrition and Species. Divine just came out with a new line. They are only selling grass fed whey iso. Top notch stuff here. TN also offers grass fed. Species is another great option. 

Then I would go to the brands you see on the supp store shelves. Dymatize Iso 100 is good, There are other good brands too. Like I said, look at the lable. If there is a bunch of aminos on the list of ingredients, stay away. Also, if it has more than 2-3g of carbs per serving stay away. Should be very little carbs and almost no fat. For instance, the TN label reads : fat 0.2g, carbs 0.8g, protein 27.3g

Hope this helps Mishko!