Only activating the goose once before needing to sink mana into it is a big deal. It will come up a lot and there are times you will wish it was a llanowar elf. I know this from my experience with deathrite shaman in cube.
However, I can't stress enough how big of a deal fixing ANY color of mana is versus just green. Birds of Paradise and hierarch are soooooo much better than llanowar elfs because of that.
I think less frequent activations is almost worth fixing for any color of mana.
We've also never played with an 0/2 flying card! The extra point of toughness will come up more than is obvious. Birds of paradise has been a crucial chump blocker against a flying KO more times than I can count. Gilded goose blocks better than any elf.
While I don't know if it's slightly better or slightly worse than llanowar elf , I'm certain it's very close and serves the same roll... The 1 cmc elves are the backbone of green creature strategies, and I don't mind increasing redundancy of them.
I like this card a fair bit. I also plan to test it and be surprised if it doesn't stick.
Any color fixing, temporary ramp, minor value through removal , multiple permanents, solid chump blocker, that's all pretty great for 1 mana.
I expect it to be competitive with the lower tier elfs.
Also, I expect Oro to make my cube, which means there could be a few cubeable sources of food, which makes both cards better.