The Alienware 17 R3 is also a big brick which is larger in size in every way. So, there's that. EVGA is obviously limited in terms of expansion due to their priority of keeping its size to a minimum. If having a bunch of drives is important to you, go with the Alienware 17 R3. Me, personally, I don't want a bunch of drives. The thing I care about most is size. Even if the laptop had the ability to add a bunch of drives, I wouldn't.
This laptop would be perfect for me if the size were a just little bit smaller. A 17" laptop doesn't fit under an airline seat. But,
if I had to buy a 17" laptop, by specs alone, the EVGA SC17 would be my choice over the Alienware 17 R3. Your priorities will sway you one way or another. Nothing can have the best of everything.