The advantage is that you're going to normally get just just as much rETH as your ETH is truly worth (minus a 0.05% deposit rate), given that Rocket Pool's contracts will right mint the rETH that you get.
The SEC is https://deweyooke828947.blogars.com/27606687/how-much-you-need-to-expect-you-ll-pay-for-a-good-rocket-pool