Well, MelissaJean, I have tiels that eat with their feet too. I also have a green cheek conures, as well as a maroon belly (that is very much like the green cheeks).
The green cheek is a much more aggressive bird than a cockatiel. None of my pyrhhura conures get along with any of my tiels. They exist peacefully, but I don't try to mix them. They are always separate.
My green cheek is a big handful. Where I can have a few tiels on me as I type on the computer or do dishes, etc..., to have my gcc on me while I try to do any of these things is almost impossible. Bebe, my Gcc, will be chewing the wheel off my mouse, tearing up the dish rag or biting at the sudsy bubbles. She lunges for the dogs if they get too close, just an all around pistol of a bird. They are big bird personalities in a small package.
A frequent mistake gcc owners make is not making the birds "step up". Because they are so small, they are often just scooped up by their owners. This doesn't gain their cooperation or compliance with a request to "step up" and therefore helps to reinforce their bossiness. It is important that your bird understands what you expect and that he receives satisfaction when complying.
Some mornings our Bebe is not immediately handleable. She needs to come out and do this posturing thing on top of her cage to warn the much larger and more aggressive male pionus that she feels she is a force to be reckoned with. Oh, little green bird, step down and behave, but no...she wants to strut and act like she is 10 feet tall. I let her get that out of her system and then she is just fine for handling.
These are feisty little birds. They are quieter than the suns (I have two of those) and they are quieter than the nanday (I have one of those), but their personality is larger than both those species. While they can be sweet, they can also be very nippy. They are way more difficult and challenging than a cockatiel. You would do well in obtaining a few parrot behavior books - and reading them - before bringing one of these parrots home.
You'll have to let us know if you get one of these or not. They will challenge you much more than the cockatiel and they will require more of your direct attention to stay tame and handleable. They are very smart and demand more attention and need more of your companionship than a tiel, for sure.