In addition to the Ci4+ composite body, the Shimano Ultegra also has a one-piece bail that allows line to easily travel onto the line roller which, in my experience, really helps reduce those obnoxious line tangles for which spinning reels are known.
Line tangles are the biggest knock I’ve always had when it comes to spinning gear. Years ago when I first started fishing tournaments as a co-angler, I’d always bring a few extra spools of line in my tackle bag because it seemed like once a day I’d get an enormous bird’s nest out of nowhere. They were the kind you couldn’t save, if you get what I’m saying. I’d have to rip all the line off and start all over.
I don’t have any of those problems with the Ultegra so far. I’ve been fishing in plenty of windy weather and I’ve even tested it with fluorocarbon main line and I haven’t had a single line tangle yet. I’m not sure of the physics and how Shimano has made this reel’s line management so great but heck… as long as it works, I’m all for it.