Hi Nate! Welcome to FT!

I suppose you are located in the US, given where you bought the item. For domestic flights there are sizers but they are usually not used. London Heathrow on the other hand is infamous for using it. And European and Asian carriers are infamous for having a 6-8kg hand luggage weight limit (but they allow free checked bags, which makes sense).

As far as the garment compartment goes, you should read the packing tips sticky on top of this forum. That'll help a lot.

The bag is also somewhat flexible. So even if you are met with a sizer requirement, as long as you didn't overstuff it, you will be able to fit it in the sizer.

For US travel I don't think you will have any trouble at all.

Till