I love the original Voogie's Angel; I think it's vastly underappreciated.
First off it has an amazing voice cast, 100% A-list: Aya Hisakawa, Kikuko Inoue, Sakura Tange, etc. The soundtrack simply rocks; the vocal pieces are all brilliant, as is the choice of OP/ED pieces for the anime. The music is great on its own but it's also very well fitted to the events of the show. Even the engineering and recording quality of the soundtracks are top tier. I've taken the CDs with me to demo high-end audio gear in the past.
Second, I really like how the show seems comedic and silly at first and then gradually gets more and more serious as it progresses. You soon realize that despite some of the funny antics at the beginning they are not kidding around at the end.
"Forever and Ever" is a compilation OVA, and like many compilations it is both great in some ways and bad in others. The vast majority of the content is the same, they just mixed-up the chronology. This means that instead of the beginning being silly and it gradually transforming into a serious show the serious and the silly moments are mixed up throughout. In my opinion that greatly reduces the emotional impact of the serious bits. But on the other hand it has some new scenes which take place right at the end of the original, and they are great. The extra content ties up a few loose ends and has some emotional impact all its own. I'd say the best way to watch the series is the original OVA episodes 1-3, and then watch the new post-final-battle scenes from Forever and Ever.
I'm not sure what to think of this reboot; the animation is sloppy, we know nothing about the story. It's nice to see Sakura Tange back but I'm not too familiar with the rest of the vocal cast. Oh, Yumi Touma is back as Teddy, as she voiced in the original. I love her singing voice but unless they've changed things drastically Teddy does not have a singing role, so that's moot.