See this post for the config that I purchased for the XPS 13.
You may stack 10%OFFXPS + $75OFF$1099PC + MPP discount (around $26) with this config... This config is also one of the few in the XPS 13 selection where you can use the 10%OFFXPS code.
Here are a few things I have considered before I made my decision:
a.) I would have wanted to use the $100OFF$1299 code but it's not stackable with the 10%OFFXPS so I ended up stacking the 10%OFFXPS and $75OFF$1099PC instead.
b.) There's not much of a difference between the performance of an i5-7200U vs i7-7500U so I chose the former.
c.) This config only has 128GB SSD drive but if ever I would need more storage space in the future, I can just upgrade to an SSD drive with greater capacity. For now 128GB will be enough for me.
d.) 8GB RAM is good enough for my use so I'm good with this even if its not going to be upgradeable (found out that RAM is soldered directly into the motherboard similar to the Macbook Air).
Don't forget to join the Dell Advantage rewards program to get $69 back through their ePromotional Card for this config.
Also, use ebates.ca to get an additional $23.23 cashback for this config.