I apologize, I don't know how I missed your question. I like both brands but I find on certain sigma brushes, they shed. I LoVE real techniques brushes, applies to the skin beautifully.

Hmm good question...im really not sure. :/

Both can work great, you need to go to the counter and get a color match done. Always ask for samples so you can try it out for a few days before making a purchase.

I use a undereye light cream, like ROC. Then I apply the corrector with my finger and gently pat it in. The using a MAC 224, I use small circle motions to buff the concealer in.
The set with a translucent powder. Works great, lasts all day for me. I think the key is not to apply heavy layers.
Hope this helps :)

My apologies, I don't understand your question. Could you rephrase it and resubmit? Sorry and thank you!