Here's another opinion from a fellow Plymouth Rock breeder:
I like the purple cockerel best.
In my opinion, he:
1. Appears to have much more growing to do....seems to have a larger frame, still looks like a "gangly teenager" right now, but I think he has a lot of growing/filling out to do
2. I like his length of back
3. I prefer his tail although my Rocks are 10+ months before I can get a good read on tails
4. First bird appears to carry a "V" shape in his underline, Mr Purple isn't "perfect" but seems to carry more curve (could be the pictures)
Lastly, if Mr Purple is a bit more fiesty....can't be all bad for fertility issues. Heads to me are about a toss up. If you are looking for improved SIZE, I think #2 is your man.