Not a no-brainier, necessarily. I won’t offer an opinion either way here since it’s outside the scope of the ZBrush Questions &Troubleshooting forum, but I would just point out the tablets vary in other features as well, like pressure sensitivity, tilt support, and available sizes.
Those things aren’t likely to be super important for Zbrush work, but if you use paint programs that support features like tilt, it’s something to consider. You need some, but not an excess of pressure sensitivity for Zbrush work–3d meshes just aren’t that demanding in this regard–but I really appreciate more sensitivity when I’m doing something that requires more finesse like digital pencil or fine line drawing work in a paint program.
Personally, I use an older (because it’s been bulletproof and won’t die) Intuos (Pro-equivalent) model with all the buttons and touch strips (albeit in a different configuration), and they’ve never been anything but helpful for me. Because I’m weird apparently, I sometimes like to hunch over my tablet propped up in front of my monitor, and they help reduce some of keyboard dancing my free hand has to do. It’s a larger tablet though, so I’m not likely to inadvertently make contact with any buttons.
I personally think getting the right size tablet for your intended tools and preferred way of working is more important than the other considerations. This is another way the tablets differ, so if you prefer a larger tablet like me, that’s going to make your decision for you. A smaller tablet is, again, fine for ZBrush. Just depends on what else you might like to do with it.