Wearing a synthetic/hydrothermal emerald will look better than a natural emerald that you bought for the same amount of money. You can get a great looking synthetic emerald for under $100.00, whereas the same looking natural emerald will cost you thousands.
If you are looking for a result from wearing the stone for energy channeling, chakra or healing purposes, you won't get good results. The reason for the poor results is that you know that the stone is not real. For you to get a benefit, you have to believe in the process and believe that you are using the appropriate tools, which you already know you are not.
If you are buying the synthetic emerald as a gift, and try to pass it off as genuine, you might get a lot of appreciation until the recipent finds out it is not natural, at which point you will be in their ill-favor for a very long time.