The question you have to ask yourself is how often you are going to use the luggage carrying system you buy. Without a doubt a hard pannier system is more secure and weather resistant but in most cases more expensive and a unique fit to you bike. If you only intend to use the system occasionally then soft luggage is probably the best choice, being usually cheaper and not bike model specific.
I want to get some accessories for my Suzuki Bandit 600 with some touring kit but I'm lost in among all the racks, panniers etc out there. And if I find something on the net, it's not available in Thailand. What would you recommend for a balance between quality and affordability? Is a soft luggage option the way forward from a weight point of view if I'm traveling two up with my partner?