I used to use the lil' plastic "highball" cups. I had several tell me the roots hated the light, but mine did very well last year despite this, and it was both fascinating and informative to see when the plants could use a pot up again.
Maybe split the diff and see if you get different results?
I'm back to using the black cubes, mainly because I get 'em for free from the local nursery.
Good luck either way.