Ninja Double Stack SL400EU XL

The choice between the Ninja Double Stack SL400EU XL and the SL300EU 7.6L primarily comes down to capacity and secondary features. Both air fryers share the identical 2470W power rating, meaning their cooking speed should be comparable. The most significant distinction is the cooking volume, with the SL400EU XL offering a larger 9.5L capacity compared to the SL300EU's 7.6L, making the XL better suited for larger households or batch cooking. Furthermore, the SL400EU XL boasts additional convenience features such as a display and light indicator, items not listed for the SL300EU. Therefore, if maximizing batch size is critical, the SL400EU XL is the superior option, whereas the SL300EU provides the core dual-basket functionality at a potentially lower cost.