how dose the samsung tab 2 compare to the mytab?

The Tab 2 is better than the mytab in many substantial ways. Better screen, faster processor, probably better build quality, and it's made by Samsung, so you might actually see a software update.
 
That's like comparing a brand new Ferrari and a 1990 hyundai. I'd at least try to compare more similar tabs like Galaxy Tab2 vs Iconia A500 or Transformer Prime