Research for a client:
For $100 less ($499) you can get a very similar model from Asus: F555LA-EH51 i5-5200U 8gb 1tb 5400rpm 15.6" 1366x768 [3]. Or for about the same price ($579) as that Dell get an even faster CPU: Asus F555UA-EH71 i7-6500U 8gb 1tb 5400rpm 15.6" 1366x768 [4].
Compare to that base Dell model, for an extra $150 (to $749) you could move up to the 7000 Series 15" Intel i5-6200u, 8gb RAM, 256g SSD, 15.6" FHD(1920x1080) 2-in-1 Touch (folds into a tablet) [5]. Same CPU and RAM, but better resolution and much faster disk, if you don't need all that extra room.
There exists a strange compromise that should be noted, an Asus with less power but with high-res screen for only $369. Its the Asus F555LA-AB31 (i3, 4gb, 500gb hdd, 1920x1080) [6]. That's a great price-point if that mix works for you, and you can see why its "#1 Best Seller" on Amazon. I think it would make a great second computer (travel laptop, tv room laptop), but not so much as a primary machine, unless your needs were really minimal.
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links:
[1] http://www.laptopmag.com/articles/laptop-brand-ratings
Amazon
[2] http://www.dell.com/us/p/inspiron-15-5559-laptop/pd?oc=fncwv2310s&model_id=inspiron-15-5559-laptop
[3] http://www.amazon.com/F555LA-EH51-Intel-Laptop-Windows-64bit/dp/B015790WNI
[4] http://www.amazon.com/F555UA-EH71-Intel-Laptop-Windows-64bit/dp/B014LE6A6I/
[5] http://www.dell.com/us/p/inspiron-15-7568-laptop/pd?oc=dncwa005s&model_id=inspiron-15-7568-laptop
[6] http://www.amazon.com/F555LA-AB31-15-6-inch-Full-HD-Laptop-Windows/dp/B011KFQASE
