Finding The Perfect Carry-On Bag

Although I write a blog about travel, I am sorely lacking in the "packing light" department. I have been working hard to do better recently, but it still seems like on every trip I take my suitcase is heavier than I would like and I always end up bringing home a few unused items. Sound familiar? Or, do any of you manage to pack for a week or more in a small carry-on? If so, will you please write a guest post to share how you do it?!

In anticipation of my upcoming Ireland trip (fingers crossed that I will be able to go!), I am challenging myself to try to pack for a week in just a 21" international size carry-on. Hmm...just the thought of that makes me incredibly nervous. 
My old carry-on bag is too big for the new international carrier restrictions AND it is the two wheeled version. With a bad arm, I need to make sure my luggage is easy for me to manage. So I need to find an ultra light spinner carry-on that can hold a weeks' worth of clothes.  
Here are a few of my options...I would love your input...which would you choose? Or, do you have another one you would recommend?
This may be the most stylish choice but how practical is it? Believe it or not it is also the lightest weight of them all, at just 5.8 pounds! Of course, it is also the most expensive.
I love that this one is SO lightweight and it looks like there may be some "give" for me to overstuff it a bit, plus I am tempted by all the fun color options...BUT, will it be sturdy enough?

 Delsey Luggage Helium Titanium Carry-On EXP Spinner
Everyone seems to be carrying "clamshell" luggage these days so they have me intrigued...definitely sturdy but will it be light weight enough? The Delsey website claims it will hold 10 shirts, 4 pairs of pants, 2 coats, 4 pairs of shoes and two toiletry bags. 

Travelpro Maxlite3 21 Inch Expandable Spinner  

This is the brand the flight attendants and pilots swear by...that should be a reliable recommendation, right?

    Victorinox Luggage Avolve 2.0 20  

All my other luggage is Victorinox and I love the brand, but this just isn't wow-ing me.  

Okay, my friends...I would love for you to help me out...which would YOU recommend?