Looking to upgrade from my toneport ux2.

Im looking at a range of $150-300 USD tops (must be sold at guitar center cuz i get a discount there).

So far these are a few that im looking at.

PreSonus Audio Box 2x2
M-Audio Fast Track Pro
Focusrite Scarlett 8i6
Native Instruments Komplete Audio 6

Looking to buy new for warranty.

My personal favorite from what ive read is the Scarlett in terms of features. Though I dont know enough about the specifics to determine if one is better than the other.

Could use some help, thanks!