The idea of cajon pads is pretty interesting, because im feeling some discomfort after playing for 1.5h, but in my opinion, this thing made it worse. at the 1st moment it was kind of comfy, but after 1h it started to feel even worse than without a pad.
Maybe it is because i have a cajon with rounded edges(Sela CaSela Pro), and it only adds some comfort to cajons with rectangular edges, but as i said in the heading, it is not my thing.
Since its only 5 EUR, i would reccomend to try it out, but i will probably not use it, or buy something more pillowish like Meinl Deluxe Cajon Seat, but if you are wondering if you should buy a cajon pad for cajon like Sela Casela with rounded edges, i would probably not, because it is already comfy without a pad.