OK, I just finished watching The Matrix Reloaded on 4K, having not seen it in probably ten years or better. To be honest, I don't think its as good as the original, but it was still a lot of fun. I do think the freeway sequence and Neo's fight with the Merovingian's goons made the story feel stretched a little too long. Certain moments with the first film made me feel the same way, like Neo and Trinity's rescue of Morpheus taking at least 10 full minutes, or longer. I'm usually patient with these kinds of things, but sometimes less really is more.
Anyway, back to the sequel: the only other downside to it that I saw, was a lack of color grading that matched what had been established in the original picture. The 1999 effort was basically split into three color schemes - blue for the real world, and either yellow or green for the Matrix itself. But in this one, almost everything was some shade of blue the majority of the time. There were some exceptions, like the scene with the Oracle and Smith's clones, plus Neo's chat with the Architect. But overall, I didn't remember the color differences being so drastic.
The UHD image was still gorgeous though; I loved the attention to detail and things like clothes, skin textures, and special effects. The so-called "Burly Brawl" still looks a bit like a bad PlayStation game, but I think that was due to a pair of things - tech limits of the time and the directors wanting to push that concept too far. We didn't need to see Neo fighting 200 Smiths to get the point across - half that number would've been enough. Thankfully, most of that sequence is accomplished in close and medium shots, so only the widest ones look compromised.
Overall, I give this one a solid 8/10. Next up is Revolutions (probably in a few days; I don't want to rush myself).