Frankly, it's shit.
The new voicework is recorded on better equipment, and the redub actors do a better job, but the scripts are still shit, they only redubbed half of the dialogue initially, less as it went on, the mixing was terrible, incorrect lines from the original recordings were used,
often to the detriment of the dub (another example is one of Garlic Junior's henchmen saying "Gohan and Piccolo hate each other"), some lines were even missing in the initial release on the Orange Bricks, and sometimes it seems the redubbed dialogue was recorded from a different script than the final recording, so some conversations just don't make any sense.
The Funimation cast redoing their old work is a great idea on paper, but the only thing that actually improved in the "Remastered dub" is some of the line delivery, which ends up being a downside if you ask me, since at least in the original dub it was uniformly bad and you could appreciate it on the level of it being like an amateur fandub that replaced the Ocean dub. But the remastered dub just continually reminds you how bad it is by having a random subset of the characters actually sound pretty good (though admittedly still not good enough to make the awful scripts work; I don't think there are many actors who could achieve that, even at the top of their game, the season 3 scripts were just something else, even compared to Funi's other Dragon Ball work).
There's also the matter of the music. If you watch with the "US broadcast score" option on the DVDs (not an option on FunimationNow), several episodes use the non-final, early placements of the Faulconer music.
If you watch with the Kikuchi score (the only option on FuniNow), you have the awful mixing, the score doesn't fit Funi's version of the show at all, the insert songs are missing, and the OP/ED (which are very important, not just because they're good and iconic, but because they establish leitmotifs used in the show's score) are replaced with generic instrumentals.
The "Remastered dub" is awful, no two ways about it.
The point of Dragon Ball is to enjoy it. Never lose sight of that.