At $620 This model is a decent performer in your price range with an HQ version i5 it will multitask pretty well, and a 128GB SSD for boot/ 1TB HDD for storage, it will boot fairly quick and have plenty of storage. It also comes with a 950m if you want to do some gaming:
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/www.newegg.com/Product/Product.aspx?Item=N82E16834315305 there is also a similar acer model for $599 with the same specs except it uses the U version i5, which is not as powerful or as good for multitasking but may give you another 30 minutes or more of battery life. These are about the best bang for your buck currently available in your price range. Some other options include:
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/www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=100020039&IsNodeId=1&srchInDesc=i7&bop=And&ActiveSearchResult=True&CompareItemList=3090%7C9SIA8HC48C0659%5E9SIA8HC48C0659%2C34%2D315%2D424%5E34%2D315%2D424&percm=9SIA8HC48C0659%3A%24%24%24%24%24%24%24 with the Lenovo having better price/performance, and the Acer having nearly twice as much battery life at 9 hours, but not the best hardware for the money.