I like the non-traditional look of the Samsung stand.
Acer shows a dynamic contrast of 100,000,000:1 while the Samsung a mere 5,000,000:1, but we all know there's no real standard for measuring or comparing this.
Acer's 3-year warranty would make my decision. I've learned the hard way on a $1500 Television that when Samsung says 1-year warranty, you can count on it to fail close to or just after the 1-year mark (my TV did both).
I would go with the Acer based on the warranty.