I've participated in a couple of recent threads seeking advice on bags, and I've been singing the praises of the Euro Flight Bag in conjunction with the 20" rolling carry-on.
I used these bags again for a five-day trip to D.C., Virginia and Maryland last week. Once again, I found this to be a great combination for my needs, at least when rolling through airports. Some people have complained about the Euro bag not sitting securely atop the carry-on, and I did for whatever reason find it to be a bit "floppier" this time than in the past, but never any big problem. And it's still worlds ahead of my previous "solution" to carrying a CPAP which involved schlepping three bags, one being the original CPAP bag which I absolutely could not secure well to the carry-on handle. Talk about floppy!
As I've described before, I use the Euro bag to carry my CPAP, minus the humidifier, and associated cords and tubing. I wrap my Nikon P530 camera into the Civita day bag, which goes into the Euro next to the CPAP. I also carry my Kindle, earphones, gum and anything else I might want to access on the plane. With that load, the Euro bag is barely half full, which makes it easy to smush under an airline seat. On our upcoming trip to Italy, I'll probably put a few other things in, such as my packable rain jacket and "don't tell Rick" bag, zipped inside a travel pillowcase, giving me a little something to rest my head on flights without carrying a separate pillow. All that will probably come in between 9 and 10 pounds.
As I said, rolling the two bags through the airport was a breeze. However, on our very full return flight from Raleigh, we had to gate-check our carry-on bags through to Peoria, connecting through Atlanta. Which meant I then needed to haul the Euro bag around with me instead of rolling it atop the carry-on (and I'll have to do that again next month, climbing stairs and such in Italy). I've mentioned before that I found the included shoulder strap to be quite uncomfortable. I'll definitely be replacing the strap, but haven't gotten around to it yet. Slinging it over one shoulder, the strap digs in a bit and part of it sticks up. The best solution seemed to be to wear it cross-body, but with the bag probably around 7 or 8 pounds this time, that was definitely not very comfortable, either. I ended up taking the strap off and just carrying it by the top handle.
Others have complained about how the lack of structure makes the bag floppy and that zipping the large main compartment is a bit ungainly. I get that, and I'd say it bugged me a bit more on this trip, maybe because it had been discussed recently.
At any rate, it's still a good solution for my CPAP/personal item needs, but if I someday spot something that seems better, I'd be willing to switch.
I will, though, again wholeheartedly sing the praises of both the RS 20" rolling-carry-on and the Civita day pack. Great bags that do everything I need comfortably.