It's true that unfortunately, money is the biggest consideration - for shirt manufacturer and sponsor alike. I'd love to stick with Nike and Pirelli for tradition and aesthetics reasons but if there are others willing to pay us more, we must move on.
That said, from a purely design point of view, I fucking hate Adidas jerseys. Their utter devotion to their 3 stripe trademark ruins designs for me and makes them so generic. It's a template which is way too visually dominant. ALWAYS 3 stripes on the shoulders and 3 stripes down the shorts. Every Adidas kit is an Adidas shirt first, and
then a Man Utd, Real Madrid, Bayern Munich kit.
Say what you will about Nike. It's true they've made some fucking dismal shirts recently, with their greatest abomination yet to come (the zig-zag shirt for next season (if there even is a next season
)) Some of their templates have been hit and miss. But generally, they have a much less "invasive" branding on their jerseys. Besides the small Nike swoosh logo, there's nothing else to draw attention away from the "team identification" part of the shirt.