Anyone using convertible luggages? Those where wheels and straps are present so you can pull them along, and you can carry them on your back anytime?
Especially those with hip belts and compression straps.
Any brands/luggages to recommend?
While this may seem like a good idea, I doubt you can find one that is comfortable to use as a backpack for more than a few minutes. The constraints of having the wheel-assembly and metal telescopic handles means that the bag will be uncomfortable to use as a backpack. Plus, it will be heavier than a regular backpack or wheelie, but with less space since it has to accommodate extra space to hide the straps and belt.
I bought one of these with the same idea, but ended up using it only once or twice, and when I used it, it was always in wheeled-luggage mode. So the convertible was never used as a convertible.
If you don't have any physical impairment, I think a good, lightweight backpack is all you will need. Just pack light, keep your luggage (including backpack) below 4-5kg, and you should be quite comfortable carrying it for long distances.
I just returned from Indonesia today. After checking out of the hotel, I wandered around town with my backpack on my back until it was time to head for the airport. No problemo, because my pack was light.