Online T-shirt Site

Hey all, if you catch this, I've been looking into possibly opening up a t-shirt store and I've heard good things but read poor reviews of Society6 and Redbubble.  Was wondering if anyone here had any thoughts on these online sites or ideas on better ones?  I was also thinking of launching with just one shirt on Teespring.com just to see what the demand was like.  Anyone with any know how step up and offer your wisdom to me .