Two Big Buttons vs. Six Small Keys
Slam Buttons and the EM Mini Pad both put shortcuts within arm's reach of your keyboard, but they optimize for opposite things: Slam Buttons optimizes for hitting accept or reject without looking, the EM Mini Pad optimizes for fitting more distinct actions into less space. If accept and reject really are the only two things you do, Slam Buttons is the better tool; if you want more than two actions, the EM Mini Pad is.
Two giant targets vs. six small ones
Slam Buttons is exactly two full-size arcade buttons on a plate, big enough to hit blind, you don't need to look down to know you've hit the right one, because there are only two and they're both huge. The EM Mini Pad packs five keys into a three-by-two grid, each one similarly sized, plus a knurled knob. For a single, frequent, binary decision made hundreds of times a day, the size and count of Slam Buttons' targets genuinely reduces mis-hits in a way six same-sized keys can't match. For anything beyond that binary decision, the EM Mini Pad's extra keys are the whole point.
What the EM Mini Pad can do that Slam Buttons can't
Slam Buttons is two buttons and nothing else, there's no path to a third function. The EM Mini Pad's knob handles volume or mute, four of its keys can be shortcuts, and the sixth is commonly mapped to something like a boss key that minimizes whatever's on screen. It also runs wirelessly over Bluetooth off an internal battery if you don't want a cable at all, something Slam Buttons' wired, bus-powered design doesn't offer.
What Slam Buttons does that the EM Mini Pad can't
Speed and confidence on exactly one decision. The EM Mini Pad's five keys are all a similar size and shape, smoked transparent caps over visible switches, which look good but don't help you find the right one by feel the way two oversized arcade buttons do. If accept/reject is a decision you're making without looking down, Slam Buttons is built for that specifically; the EM Mini Pad isn't.
The honest middle ground
If you genuinely need more than accept/reject but still want big, blind-hittable targets for those two specific actions, you may end up wanting both eventually rather than choosing one over the other, they don't compete for the same desk space, since Slam Buttons sits flat near your hands and the EM Mini Pad is small enough to tuck beside it.
Who should skip both
If your review cadence is light, a few decisions per session, not hundreds, neither device is solving a real problem for you. A keyboard shortcut is free, takes zero desk space, and won't sit there unused the way an underloaded macropad or a pair of buttons you rarely press eventually does.
For the foot-operated version of this same decision, read Slam Buttons vs. Pedal Three, or see the full comparison hub. Setup notes: EM Mini Pad for Windsurf.