You have to pick:

Tsh, who says I know these people?

THIS WOULD BE AWESOME.

So, no change from normal.

Perhaps. Becoming a unicorn would give you magical powers and becoming a pegasus would give you flight. But an earth pony? All they get is pity. ;)

Either way, you'll be a freak (seeing as talking colorful ponies are not normal in real life). The unicorn might be worth it. The pegasus I'm a bit more dubious. Earth pony - that would suck.

So you're taking a risk.