4 is the way to go. The ergonomics are vastly superior and it's much easier to navigate tight/crowded spaces pushing your bag in front of you as opposed to dragging it behind you and worrying about bashing into people, especially during boarding/de-boarding. For short weekend trips I try to get everything in my backpack, which I can easily stack on top of my roller. I recommend Away or Briggs & Riley. I'm not one for luxury brands but if I'm going to use something often I'm willing to spend a premium for quality and functionality. I use a Tumi Alpha 2 T-Pass backpack (I got it now from Nordstrom Rack for under $300) all the time, sometimes without a carry-on. I used Away for quite a bit until I just recently upgraded to the B&R ZDX 22 Expandable Spinner. The B&R is the most I've ever spent on a single piece of luggage ($459), it even cost more than the July checked spinner trunk I recently bought. IMO it's worth it as I'll get way more use out of it than any checked luggage. And the price is actually pretty good for what you're getting. It's expensive but competitive with the more premium offerings from TravelPro. Compared to Tumi and Rimowa they're a bargain. And that warranty can't be beat.