Technically, there's nothing wrong with Byrd's playing on 'Fuego', at least not in my opinion. Musically, it's neither much better nor worse than his other Blue Notes of the day; it doesn't stand out from his late 50s output in any way. His tone was never the fattest among trumpeters, and it could sound somewhat uncertain from time to time. He sounds OK here, though, but plays it rather safe.
Edit: As usual, just my very personal opinion of the date. (added after reading the praise in the previous post. I guess I'm just not a great Byrd fan, though I have most of his Blue Note albums which I enjoy for what they are; mostly solid and not too adventurous hard bop dates)