Hey, I would say there are two major points to consider here: software & hardware. For software your Pixel 6a will get updates until July 2027, which one of the Nitrophone's key features security wise. So, if this is your main concern there is not really a strong argument (despite even longer software support) for replacing your Nitrophone right now. Hardware-wise on the other side the newer models come with better hardware and thus better performance. Most notably are likely the (massively) upgraded cameras and the new Tensor G2 Chipset, which might improve batttery lifetime. For more details hardware-wise you can find lots of comparisions online.