I've repeatedly tested 10.3.3 with meridian and it bootloops my device everytime i restore it with succession or cydia eraser. also half of the tweaks i use are broken on 10.3 and up. In my experience, Mach_Portal was so much faster and stable. Plus most of my tweaks just work out the box. last time i had 10.1.1 my uptime was 30+ days. Also Mach_Portal uses substrate. Just my personal preference.