Instruct: Classify Amazon reviews into positive or negative sentiment
Query: UNRELIABLE PRODUCT, GREAT TECH SPECS

I BOUGH THIS UNIT AT BEST BUY 2 WEEKS AGO AND HAD TO RETURNED AFTER DOWNLOADING A FEW SONGS. THE UNIT WOULD JUST NOT BOOT-UP AND THE BLUE LIGHT ON THE FRONT BUTTONS REMAINS LIGHTED. NO SCREEN, NO MUSIC, NO NOTHING.AFTER SPENDING 3 HOURS ON THE PHONE WITH CUSTOMER SERVICE AT SAMSUNG WITH NO RESULTS, I DECIDED TO EXCHANGE THE UNIT THINKING IT WAS A HARDWARE PROBLEM. THE NEW UNIT HAD THE EXACT SAME ISSUE, IT WORKED LIKE A CHARM OUT OF THE BOX, BUT AS SOON AS I IMPORTED SOME MP3 SONGS INTO THE UNIT, IT STOPPED WORKING!. I'M A COMPUTER EXPERT SO I KNOW I DID NOTHING WRONG. I RECOMMEND TO BUY A PROFESIONAL PRODUCT (SUCH AS THE iPOD) AND DON'T WASTE YOUR MONEY OR ENERGY ON A BAD PRODUCT WITH IMPRESSIVE SPECS.