Are you sharing bandwith and with what?
Where do you connect to when using steam?
Steam Spiral Knights client is identical to the standalone client with a few added connectivity features for syncronising Steam Account functions with the game's functions, and an inbuilt usercheck function that converts your steam account name into your "ID" which is a preset jumble of numbers that functions as your username.
So no, you aren't sharing any bandwidth, within the client itself. That being said, steam does have a miniscule increase in bandwidth to make sure your cheevos and inventory are synced. (Compared to having steam open and the standalone client open simultaneously)
That's my assumption, which shouldn't be too far from the truth.
Thank you for your replies. If these had a solved request subforum i would put this there, but it doesn't so i'll graveyard this.
IIRC you connect to the same nodes that players using the official client do.