Sure,too small is no good to anyone ;-)
I know what I need to carry,and I know I'm not going to go shopping much when I travel.So I use what I need,which happily has a lot of advantages.
A 20l would be too small for me,but some people travel with that....
i am only five and a half foot tall but my rucksack is 80 litres so your theory is not perfect
Was useful to have extra space when in Tanzania or Malawi where at the higher altitudes some warmer clothing was suddenly required mainly for the evenings
Thank you all so much. Would you recommend the Osprey Fairview 40l and get a foldable stuff backpack to put inside or the Fairview 55l which would still be the 40l and 15l daypack attached? Suppose it is essentially both the same thing right? I’d like the 70l backpack so the actual pack is 55l but doubt I’d need the full 70l.
You've already had all 3 answers depending on whom you ask. You're going to have to add additional criteria if you want even more different answers ;-)
If you're asking me ?, your last option is the best - you don't have to fill your bag but you've got the space if you need it.
Suppose I was wondering if I had to buy a foldable day back with the 40, if it was more cost effective to go with the 55. Which is essentially the 40 and a 15 day pack. However I’ve watched some YouTube videos and seen some people just take a normal day pack with them rather than a foldable and fit it in their (husbands) bag.
The 55 is just the 40 with a front pack attached.
For me,as I said,its a waste to have that extra.I don't need the space,and I don't want to check it in (which you would have to do with that).
It depends on you of course..if you need the extra space,and if you are happy to check in your luggage (and pay for that).
The extra price of the bag is not much difference.That's not where you save the money....
That other option...a normal day pack fitting into a bigger bag...is also an option of course.
But it kind of defeats the object I think.If your main bag is big,you don't need to fit the daypack inside it.You will need to check in the main bag,and you can carry the daypack as carry on.
The idea of the ultralight bag is that it weighs very little and rolls up very small,so its easy to transport even in a 40.Then you can use it when you are in places,without needing to carry the 40 around every day....
The daypack, irrespective of foldable or removeable, would always be hand luggage for me and not something to fit into my husbands bag. I don't carry a handbag on longer trips and there are are too many indispensables / valuables to risk losing in check-in luggage or pile-high luggage on ferries and buses.