I began watching the English-language broadcasts on Fox, because they had the 4K. Their 4K picture wasn't much as a 4K, and the regular HD on Telemundo wasn't too bad, so I ended up spending almost the entire Cup watching in Spanish.
For the most part, I didn't catch enough of the Fox teams to make an evaluation. From what I did see, the team of Derek Rae and Aly Wagner was quite good. Probably the best thing about Fox was that no one sucked ... we've come a long way. I mostly skip in-studio pre-and-post-game shows, so I have no opinion there.
The lead team on Telemundo was the legend, Andrés Cantor, with Manuel Sol as analyst. They've worked together for a long time and have an easy feel. The other play-by-play announcers are Copán Álvarez, Jorge Calvo and Sammy Sadovnik. I'm a long-time fan of Sadovnik ("aroma de gol!"), Alvarez is solid, and Calvo didn't make enough of an impression on me to say much. Telemundo have had a variety of analysts ... they seemed to have three people in the booth for every match, and they tended to bring in at least one person who was from a country in the particular match. Cantor was ebullient whenever things went well for Argentina, but all of the commentators with a personal stake did little to hide their loyalties, and it was kinda fun, to be honest. The quality of the analysts was OK across the board, without anyone standing out too much. But I'd mention Natalia Astrain from Spain, the USWNT U-17 coach who has been interesting. Also, my daughter and her husband enjoyed Brazilian Mauro Silva ... they found his accent when speaking Spanish delightful.
No real surprises in any of this. Well, I wish the Fox 4K picture had been better, but then I wouldn't have spent most of my time enjoying Cantor and company.