This isn't nearly as good as Chandra's Phoenix which comes back to the field instead. Not only that, it comes back far more easily. Chandra's Phoenix can come back anytime you deal damage to an opponent via a red instant or sorcery spell or by a red planeswalker you control. So, Firewing Phoenix is a greatly inferior version.
Don't get me wrong: Firewing Phoenix was a nice Limited card because it's a flyer and can be brought back fairly easily in a mono-red deck. But four mana to get back a 4/2 flyer in a mono-red deck is probably mana better spent in just about any other format. It's not even too good in Limited in anything other than mono-red due to the heavy investment in Red that's required!
Obviously, Firewing Phoenix was never the Standard staple that Chandra's Phoenix was each of the times it was in Standard. It's a case where Wizards realized that they made a card a little too good, so they designed a greatly watered-down version in the next Core Set. It has beautiful artwork, but that's about all it's got going for it in the long run. It's pretty janky and doesn't see play in any format, really. It does find a home in the occasional Jaya Ballard, Task Mage Commander deck, though. Really, it's just nice to have a foil version of to bling out your binder. Who doesn't love a shiny phoenix?