This is the 7th generation model: https://www.amazon.com/...06XFGF7SN/
And this is the 6th generation model: https://www.amazon.com/...B9HQI2KE75
And I believe this one is also a 7th generation from the Dell website: http://www.dell.com/...I4In1dfV19
I also saw some good things about this one, the Lenovo Y520, but it's pretty high on price tag. I'd like to spend around $800 if possible: https://www.newegg.com/...13721&SID=
Mainly I'd like to know the differences between the first two (which one is better) because those two are most near my price range. If you can help me out it would be awesome, thanks!