Very impressed with Composer 2.5 after about a day of usage. I've almost moved over to it exclusively from GPT 5.5, even using it for planning now.
It's like Opus 4.7 on steroids, crazy fast. Fast models really get me into the flow of building, which is exhilarating.
Also, a sneak peek of a weekend mini-project I'm building: a racing game where you race your mouse cursor.