Rental advice- X3 or Mercedes E Class?

[chicagox7]

I posted this in the X3 forum- though figured I’d try a broader auditance as well…..

We’re heading to Ireland this summer (family of 4- kids are between 9-6). We will be doing a bit of driving around and don’t mind longer drives (have an X7 here). I used an X3 for a day as a loaner once and it didn’t leave an impression on me (good or bad). Now I’m looking at options for us to rent a car and it seems to be down to an X3 or Mercedes E Class sedan. Two things are important- overall comfort and ability to securely fit 4 carry ons and 4 backpacks (securely- out of sight).

Curious if anyone has experience with both vehicles to get a sense of which direction we may want to go. I don’t think SUV vs Sedan matters much for the trip- again it comes to overall comfort of ride and ability to fit the luggage securely (we’ll be bouncing from hotel to hotel so will be parking with a full load at some attractions; prefer to have a full load when we return from the attraction!).

(Not to complicate this too much- though an Audi A6 also pops up on some rental sites… oddly the companies we’re looking at don’t offer a 5 series (other companies we’re not looking at indicate they may offer those). My working assumption is that the E class would be better than the A6; though happy to hear if that is a materially uninformed assumption).

Any thoughts/feedback would be greatly appreciated.

Thanks!