Ultrabook Specs and Advice

[Daak12]

I'm shopping for a used laptop / tablet combo in the 200-250 range. I have it down to a Surface 3 (regular) and a dell XPS 12 convertible. The XPS line is confusing so heres more info:
"Dell XPS 12 9Q23 Convertible i5-3317U 1.70GHz 12.5" 4GB RAM"
Anyway, one has an Atom quad core and the other has an i5 dual core.
Which has the more powerful processor and is more powerful in general?
Is there something else for the price that blows these away?

 

[boosted1g]

i5 dual core is better
The atom is much much weaker so 4x Atom cores < 2x i53317U cores.

Nothing for $200-250 will "blow it away"