If you have a bigger budget, a hard cover would be more appropriate as it offers you better protection against elements and burglary, more strength, and higher durability. But if your budget is tighter, a soft cover would be the better option as it’s cheaper. That’s not to say that a soft cover has no other benefits; it offers you a sleek look, and is easier to install and handle than a hard cover.
On the other hand, keep in mind that a hard cover offer a more low profile look than a soft one, as it sits only an inch or two above the bedrail.