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I would take the one with more ram since you cannot upgrade the ram in the future. The i7 is clearly a better processor but double the ram easily makes up the difference.
 
If you're going for a refurb, you might be pleasantly surprised -- I ordered option 2, and ended up getting an i7 for free, so got the best of both worlds.

looks like I am not the only one! this happened to me as well!

ordered the 2.6ghz i5, 16gb rm, 512gb ssd... and i received the 2.8ghz i7, 16gb rm, 512gb ssd...!
 
Even though option 1 has a 2.8GHz Dual-core Intel i7, while option 2 has a 2.6GHz Dual-core Intel i5 would you say that 16GB RAM of option 2 plays a more significant role than the processor speed and intel i7 of option 1?

Yes, 16GB RAM will help more than the small processor boost.
 
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