Greetings everyone:

I will be flying CX in May 2016. CX from SFO to PVG via HKG, CX/KA from PVG to HKG and then in June 2016, CX from HKG to SFO. All of these are on Economy Class (N). My question is on the carry-on baggage size:

On the website, it says 1 piece 7kg/15lbs max with the following dimensions:
Max height ( H ) 23cm / 9”
Max width ( W ) 36cm / 14”
Max length ( L ) 56cm / 22”

The Mytripandmore.com information where my electronic ticket record is seems to show the 15lbs max and total of 45 linear inches without mentioning dimensions. Does CX/KA actually use the 3 dimensions or do they only only look at the total linear inches? Anyways, my question is that I've been trying to shop for luggage both online and offline. Offline, the stores told me it's 22x14x9 which is what the manufacturers claims as the size of the luggage except they don't seem to measure the wheels so it's more like 24"(L)x14"(W)x9"(H). None of the stores seem to actually measure the luggage they sell. ebags.com said their dimensions meaures everything including the wheels and handles so I bought a Victorinox Werks Traveler 5.0 22" Dual Caster which they claim measures 22"(L)x14"(W)x9"(H) including handles and wheels except when I received it which was shipped by Victorinox is actually 23"(L)x14"(W)x9"(H) because of the wheels. So what I am trying to ask is for those of you who travel by CX/KA, are they very strict on the dimensions or will they allow that 1" extra in height due to the wheels for carry on luggage? Also, for the personal item, they do not specify a size but if I used a larger backpack and only had the laptop in it, if you pressed on it, it will be the same size as a laptop bag or briefcase as the backpack will be mostly empty, will this still count as a personal item since the part of the bag that is not filled can be flattened. Thank you for your time, attention and assistance in this!