Growing plants under 600w and 400w whats difference would the 400w lamp do

As the title says, I am just wondering if there is any difference?? when using a 400w and now i am adding a 600w to 11 plants, I am wondering would there be a light difference over the 400w side?

Deeper penetration and bigger footprint and more light. It's all good.

Rotate your lights once a week..or use 400 for veg and 600 for flower..

I have a 400W and a 600W
I use the 400 for veg with a MH bulb
and the 600 for flower with a HPS bulb.

its awesome!

use them both to finish out your group...
but afterwards...consider breaking them up.
that way you can always have some ready to flower...and always have some flowering...

Thanks for the reply guys, I will let you all know about the process as it goes along,
Rollitup Epic site for Getting help, Really appreciated