Re: Fix+
FIX+ is great a great product to use when layering various powered typed products. For example... you could set your liquid foundation with a powered type product such as Select Sheer Pressed Powered then use FIX+ to set that power before applying contouring powered products, then FIX+ again before applying blush. This will prevent over blending (to where layered products become muddy on the face by totally blending together) and it will prevent powered type products from moving around too much on the face when layered over each other.
FIX+ also melts, if you will, the top layer of powered products to the face creating a close, snug fit allowing your MU to lay closer to you skin creating a more realistic radiant texture instead of that powdery texture left by powered type products.
Texture is preference. FIX+ just gives you another option to better create the image you desire.