After discussions on a for sale post, lets have a chat about our luggage preferences.
Love a topbox
Most useful thing on the bike
Topboxes good too, on a bike
Already been said...
Hard for security. Top loaders are way better.
Soft for trip with lots of off-road if security less of an issue.
Unless you're riding with a pillion (or camping I suppose) there's no need for a top box when panniers are fitted. If you need one, you've got too much stuff. all you need for a helmet is a cable lock...