A custom made golf driver can be a good thing if you have a lot of money, and are willing to invest both time and money on going to a custom maker. You probably have to have a low handicap or have played the game for quite a long tim. However, if you are a beginner, it isn't worth it.
I believe that in the end, if you can hit a driver (or any club), it doesn't matter if it is custom made, or store bought. Do you think Tiger Woods or any pro for that matter, couldn't hit a store bought club well? Of course they could. If it will work for them, it should work for you.
Price may be an issue, depending upon where you are planning to have your custom-made driver built. From a technical standpoint, the custom-made driver can improve your ability to hit the ball, since the club length and swing weight can be adjusted to the your own personal height and strength. Store-bought clubs are generally designed to fit the masses.
In my opinion, custon made golf drivers are better then store bought. The reason custom made drivers are better is because they are built to fit your body size and swing.