Quick Question: Expense Ratios (gross or net?)

Hi folks,
I am looking into rebalancing my 401k… I signed up on day one but basically chose funds based on zero understanding.  I know that I should look for low expense ratios but that is about it.  My employer offers a 401k through wells fargo with a bunch of options.  If anyone has any suggestions for what I should be looking for that would be welcomed!Basics:
I am 27.
I make about 46k / year.
I currently have about 26k in my 401k, 19k in Roth
I contribute 11% with a 4% match (I also max a Roth)
I have a long term outlook and am generally comfortable with risk
My ultimate goal is to be able to have more flexibility: FI for basics, and ability to work on my own terms for fun $, travel, etc.
I own my home (with my husband) and refinanced using HARP: 15 yr mortgage at 2.89% on 175k mortgage, home worth around 140k.
I have about 26k is student loans at 6.8% (grad and undergrad) and am currently using all extra income (outside of said retirement savings) to pay these down.

My basic question is if I chose funds based on expense ratios, should I be looking at the gross expense ratio or the net expense ratio?

If anyone has further suggestions or areas I should research I am open.
Thanks everyone!  I don’t comment that much in this community but I am always scanning these boards and really appreciate MMM and the community for what I am learning and providing encouragement!

Savings Account Suggestions

Where do people park their short term/emergency savings these days?  In an online account? And if so, which one?  We are embarking on some large house repairs this year and are looking for a place to park money that we can access fairly easily, but we don’t need it to be attached necessarily to a debit card or physical bank.