As a Qualcomm loyalist who's owned many Qualcomm powered phones which performed great, I'm sticking with Qualcomm. While Media Tek has made great strides in closing the gap vs Qualcomm and has become very competitive with their current flagship dimensity 9300 SoC, I prefer the Qualcomm snapdragon 8 Gen 3 SoC since Qualcomm is the more established and reputable company as well as the majority of softwares being more optimized for Qualcomm. And I feel the same way for the upcomings dimensity 9400 and 8 Gen 4. Qualcomm is the proven overall winner historically.
The alleged performance of the MediaTek Dimensity 9400 has leaked thanks to Digital Chat Station on Weibo. Based on the leaked Geekbench score of the Dimensity 9400 and the previously revealed performance of the Snapdragon 8 Gen 4, both chips are close to each other in multi-core performance.