If I were to buy a 4-ball roller (thinking about it, but for the money, I can get another ball <g>
, I'd get a stacked 2x2 one instead of the inline one for several reasons. First, my 3-ball roller is already tipsy from side-to-side. Unless I come over bumps square (even small ones), the thing wants to twist on its side.
Second, as others have said, it takes as much room on the floor as a 3-ball bag, basically three balls long. A 2x2 stacked only takes up the space of two balls.
Third, you can remove the top half of a 2x2 stack and put the bag in your car in two pieces. My 3-ball bag is heavy enough, even with my wife's 12# ball instead of a 15#. I don't want to pick up four balls at once any more than I have to.
Fourth, I don't want to lose that much space up top to the fourth ball. The 2x2 stacks look like they have more space more sensibly divided up.
Finally, most 2x2 stacks will accept a third row, and kits exist to add them to make a six-ball bag.
Oh, yeah, and if you don't mind last year's bag (and can find one), RG makes one that's red.
SH