There no longer is a generally applied IATA rule on cabin luggage. All airlines make their own. Permitted size and weight differ by a few cm or kg, i.e, from 5 to 20kg and most in the 7 to 8kg range. Many airlines in addition allow a "personnel item" which could be a hand- or laptop-bag. Its weight may count against the allowance or not. Use it to unburden the larger bag from heavy items or from valuables. There is no choice than to read the small print and, if it matters to you, to compare. Kitchen or bathroom scales are not accurate on luggage. A small luggage scale, comprising a grip with display and strap, costs only a few € and avoids surprises. On business trips, with a full-size laptop, paper documents or other gear, it is difficult to remain within the weight allowance. Otherwise ebook readers, smartphones and tablets made it easier.
The notourious budget airlines make money by selling extras. So the weigh and measure. Some even determine unusual sizes in order to trap their customers. Many discourage check-in luggage in order to minimize the turnaround time at the gate. These may have more generous allowances for cabin-bags than regular airlines.
All other rarely do, unless you, or too many other passengers for a flight, try to get by with obviously oversized or overweight bags. So avoid that obviousness. An overweight, but small bag may get through. But in case your are asked to check-in the large bag, be prepared to transfer your valuables for carry-on, e.g to your "personal item". On small commuter planes with limited storage in cabin you have to do that, anyway.
Roller bags are popular, but there is no universal advice in favour or against. Wheels and handles reduce payload and useable space as against the allowance by at least 1.5kg. Vice versa they increase the weight to carry over rough footpaths, stairs or to lift into overhead bins. They however make sense to stack other luggage, for travel by car, bus or train when weight is not critical, with barrierfree, smooth surfaces in terminals, hotel or office corridors. Hard bags appear rugged, but not necessarily they are. A soft bag is lighter and more flexible with regard to the variable size allowances or for storage in cramped luggage bins.
In 25 years of international travel by air I had five damaged or delayed pieces of check-in luggage, but never ever a lost or stolen piece. On arrival, immigration for non-Schengen citizen takes a little bit longer. You don't gain much time by not to check-in luggage.