Hard luggage is definitely nice, but for me it came down to price and use. I use me soft luggage maybe three long weekends a year. I don't two up when I travel, so that gives me extra room to strap down a dry bag if I need to rake more stuff. Given I can't carry a sheet cake across the state but have never had a reason to. When the wife and I do take longer trips she will take the HD and usually I end up with less on the busa for a 10 day trip than I do for a long weekend.
As far as security goes hard bags may be a bit better but let's face it not much. If a waste of oxygen thief wants in your hard bags it's going to take about two seconds longer than soft bags. For that matter 10 seconds and they can have the whole bike.
I wish I traveled enough to justify the price of hard luggage but I can't. To be completely honest if I could I would probably just spend I little extra and get a nice third wheel trailer and not have a single bag hiding the sexy lines of my bike.