To me this is an easy one. If you are going to be backpacking (moving between locations every few days to a week) especially in developing countries such as those in South East Asia and Central America. It makes sense to bring a backpack. It’s so much easier to grab it, chuck it on you back and take in anywhere. (There are literally 1 metre wide holes in the pavement in some places I’ve been – Good luck traversing that with a suitcase). A backpack also gives you the freedom to rent a motorbike or take motorbike taxis and bring all of your stuff with you this really helped when travelling on a budget as it meant I didn’t have to splurge on more expensive taxis or tuk-tuks (these can really add up especially when you are travelling solo!)
Of course, some people prefer to travel with a suitcase and there are some benefits of doing so such as being able to fully unzip and access all your stuff easier and being able to pull your bag along with effortlessly in the airport instead of carrying it on those long travel days. If you are not able to carry a backpack then a suitcase will likely be possible just a bit less convenient. In more developed places such as Australia or most European countries you should find travelling with a suitcase much easier due to better roads and infrastructure.
If you do choose to go with a backpack I recommend going with one that unzips and opens like a clamshell. It’s so much easier to find what you are looking for than with a classic top opening “lucky dip” backpack.
