Here's some pictures of three of my Buckeyes, the two roosters I'm probably going to keep, and one hen.  Sorry the hen is so out of focus, these are just some I had on hand.

Roo1

This is I THINK, the best Buckeye 'type' of the four I have… but he's a little aggressive.  I can deal with this myself, but I'm not positive I want to. he may go to freezer camp.

Roo2

This fellow is less of the type, but still good.  And he has a nicer temperament.  He's definately staying.  I don't have one of Roo3 or 4.  Roo4 is too slim and narrow. He's not staying.  Roo3 MAY stay and I'll keep 2 & 3 because Roo1 is just a bit too determined to stay Roo1.  I don't really need to deal with nasty roos though. 

Here's a hen… no clue which one, I need to get some color coded leg bands so I can start to decide who is who and which I will hatch eggs from.

The lady that developed Buckeyes (Mrs Nettie Metcalf of Warren, Ohio) used some of the same breeds that are in the background of the RIR when she bred them, one thing for sure is that Buckeyes have a small pea comb, which is especially good for our cold damp winters but RIRs have a single comb.

I copied this from the description in the 'American Livestock Breeds Conservancy' 

The Buckeye should not be confused with the Rhode Island Red, even though they share some history. Buckeyes are unique in their body shape: slanted, short but broad back, very meaty thighs, powerful wings and breast. They appear very close to the Cornish, as bred in 1905, in body shape. (It should be noted that the originator indicated that she did not use Cornish in their breeding; the Cornish body shape was simply her goal.) In color the Buckeye is also unique. The color of the Buckeye is darker than that of the original Rhode Island Red (later, the Rhode Island Red was bred for a shade of color even darker than the Buckeye). The Buckeye also has a slate colored bar in the undercolor (fluff) of its back; the Rhode Island Red’s feathers should be red to the skin. Both breeds share the trait of tight feathering – unique in the American Class of poultry.

Buckeyes aren't supposed to have any white on them at all, that's something that shows up in some birds so I'm going to be watching closely for that!  I'm a little afraid mine have a little too much black on them, I'm hoping it's because they're still very young… I'm waiting to hear some opinions of some knowledgeable people I know about a few things with them.