Robert Heinlein examined this idea in "Time Enough for Love" and, although his protagonist wasn't confined solely to Earth (they had developed space travel) he became incredibly bored. He had lived for lifetime after lifetime, had learned a great deal about many different disciplines, and finally concluded that there was nothing new left for him to do. He decided to kill himself because he had grown tired of living.
I think we'd all get very tired of doing the same things over and over so I'd say it's a curse, not a blessing.
Although being an eagle for millennia on end would be amazing, eventually there would be nothing left to discover, no where to soar that I had not been to before. Boredom would set in........then what?