I will be taking a backpacking trip through SE Asia, South Africa and South America for an extended period of time.
I am taking a 36L backpack, and trying to bring as few things as possible. However, I will be carrying a laptop, DSLR camera and some other electronic gear so that I can work while traveling.
Is a pacsafe, or something else that surrounds your backpack for security reasons, a necessary or useful item that would warrant the extra space and weight in my pack?
I take a padlock with me. I only use hostels that have lockers that I can attach my own lock to (not one where they give you the combination). If I am couch surfing, I lock my bag up with it. Maybe this is just paranoia, but I feel like using an anti-theft backpack device just makes you stand out...
I also don't think it helps too much. My brother and I flew down to Peru a couple years ago. He had a security net over his bag, I didn't. On the Lima to Cusco leg we both had some stuff stolen... neither of us keep anything of value in checked bags, so they just stole some toiletries.
For South East Asia, I am not sure how much a Pacsafe will help you in protecting your equipment and keeping it safe. Outright bag snatching or theft is what usually occurs, rather than someone slitting a backpack open (although that's not to deny the latter can happen too). Generally, South East Asia is a safe place and your things don't get stolen. You need specific situational awareness, such as the fact that there are motorbike-based bag snatching gangs in Phnom Penh or that when travelling by bus in Thailand, some unscrupulous private bus operators might rifle through your luggage when the bus is travelling (but this doesn't happen in other countries).
I also agree that if you are carrying an anti-theft backpack, that probably only makes you an even more lucrative target looking at stealing bags!
Since you're carrying costly electronic equipment, a better investment would be a backpack that is actually waterproof, with isolated compartments specifically for laptops if you can find one. Don't skimp out on this because depending on when you travel (rainy season in SE Asia can last months) or if you travel by boat on any stretch, that's the kind of protection - from natural elements - that you will need far more.
I think it's very useful. While it's true that you should just a padlock and locker, it's just very nice having the flexibility to lock a bag up at any point. Let's be clear: I'm not talking about more portable pacsafes that secure with just a zip that can be ripped open; I'm talking about the wire mesh bags. They can be taken too of course, but you have more options in terms of putting them in a visible area.
