Tying card draw and Lifegain to a sacrifice outlet is pretty good
With no weakness, resistance against Fighting-type Pokemon, and a free retreat cost, its not the worst
A big key to the Angel's success or failure is whether it can win fights against its most natural enemies, which leaves it coming up a little short these days due to a wealth of 4/4s both on the ground and in the air but in an era full of bears few combats were a problem
The more important reason Gaddock was contained was that green wasn't a natural fit for the decks that wanted Gaddock, or in some cases green was but white wasn't, and his legendary status made it difficult to go too far out of the way to get him
Its attack, Wondrous Cotton, can deal 50 damage per Trainer card in your opponents hand, again for the low cost of just 1 Grass Energy