I just bought this pack (small) and have second thoughts. I'm 140 lb, 5'6" athletic male and size wise small seems okay. However I have second thoughts in terms of its weight. I was considering Atmos 65 and this pack. I would in Alaska for 10 days, mostly touring the state in the car or camping or hiking (no stays hotel). I wonder if this pack is too heavy for backpacking and I should get Osprey Atmos 65 (which weighs about 3+lbs compared to primero's 5lb). Is Atmos 65 would server better than Primero for me? Also would these bags qualify as carry on luggage in the flights or I will have to check them in? Any suggestions would be greatly appreciated.
Thanks,
Anu

Tech Specs:

Material:

630D Nylon 

Volume:

[S] 3950cu in (65L); [M] 4300cu in (70L); [L] 4600cu in (75L) 

Suspension:

X-Radial with 7075 aluminum stays, E-VAP shoulder harness, E-VAP 3-point hip-belt 

Hydration Compatible:

Yes 

Torso Adjustment:

Yes 

Detachable Pack:

No 

Sleeping Bag Compartment:

Yes 

Rain Cover:

No 

Access Types:

Top, side 

External Pockets:

1 Lid, 1 front, 2 side 

Snowboard Carry:

No 

Ski Carry:

No 

Gear Loops:

2 Trekking pole 

Ice Axe Loops:

2 

Shovel Pocket:

No 

Weight:

[M] 5lb (2270g) 

Recommended Use:

Weekend backpacking trips 

Manufacturer Warranty:

Lifetime