Both me, my brother, and sister-in-law have worked for Sears. I was working part time and I liked working there. I was stocking so I worked from 5am-9am M-T and 5am-3pm on Fridays. For the most part, there were only 6 of us there in the mornings before the store opened so we would have the stereos cranking...The only reason I quit was because I had a better offer for a full time job... I have never worked at Lowe's. But, as you said, at Lowe's you would probably get some type of employee discount on melamine, wood, and AccuRites...
In the end, it will depend on what your goals are as to which place will be better for you. Good Luck and congratulations...