This product was mentioned in
with an average of
Since the bag isn't very big or heavy (only like 10kg if you're doing carry-on weight), I don't really mind not having a waist strap. I think the longest I've carried it consecutively for is maybe 2 hours at most. It's really just to get me from city to city, then I use a smaller daypack for sightseeing and such. No rain cover, but plenty of space inside the backpack for an umbrella ;)
If you are going now (not that cold) you can get by with a farpoint 40 and one of this [link]
I traveled with that in winter and was fine. I used the big pack for moving between places and the small one to walk around.
With the 55 I would be afraid of having to check my luggage.