Well, after reading SharonB's suggestion in the Joggles class forum that I try circles on linen and then taking a good look at my circle on Aida... I'm going with the linen. I think I'll start fresh on the Week 2 sampler (from the Personal Library of Stitches class), using the hand-dyed linen I got originally:
Luckily I haven't done much yet on the Aida!!