Lots of debate Hard vs. Soft. A ton written here and elsewhere. I've used both going back over 20 years and 4 or 5 different bikes including a Vstrom.
IMO, a key issue concerns how much Off Road is intended. Using hard bags adds substantial weight with bags themselves and the racks that support them.
On my DR650 I eliminated 35 lbs. (16 kgs.) Givi hard bags + racks, hardware. On the DR650 this was huge and I could really feel the difference off road. Wow!
Also, more weight can mean bike and components get beat on harder, things can break: racks themselves (common problem), wheels, Shocks, Sub Frame, premature wear on bearings.
If riding primarily ON Road then, IMO, hard bags are OK, but don't cry when you get to that technical muddy 5 mile detour and the bike falls over 10 times or you have to ride 20 miles of horrible Wash board corrugations. (frame breakers!)
Weight is critical!
Never assume gear is safe in a hard locking box. Yes, locked hard panniers typically will put off amateur snatch & grab thief but won't slow down anyone serious/skilled. Most locks on hard bags can be busted into in 1 minute by a 14 year old with a screw driver. But they DO look secure to unschooled and keep most honest people honest.
The best thing about hard bags is when stopping briefly in a city/town and want to do a "walk around" without having to Lock Down the whole bike. But chances are you'll still have to remove a fair amount of items before leaving the bike: GPS, Comm's equip., tank bag, tail bag, ect. ect. So no perfect way here.
Plusses to Soft Bags:
1. Weight. This, IMO, is the big one. 2. Better crash survival than hard boxes.
3. Less chance to trap and break your leg the way hard bags do.
4. Use waterproof INNER BAG LINERS for grab & go convenience at hostel or hotel. Panniers stay ON the bike, only inner bags go inside. Off/On under 30 seconds. (of course you should use inner bags with hard bags too!)
When stopping you can either find secure parking or have someone watch bike (its cheap!) Or ... use a Pac Safe steel cable system. Quite good!
I don't like GL bags. Too hard to see what is inside and too hard to find anything without pulling the whole bag OFF the bike. I prefer pannier style where I can stay organized with various compartments. Use colored stuff sacks in any case to make finding things easier/faster. GL bags also ride TOO HIGH and put TOO much weight too far back. Soft panniers can rider lower and further forward for better Mass Centralization. Critical for good handling.
A ton more Plus and Minus for both systems. I use hard panniers on my 1050 Tiger (highway only) but only soft bags on my DR650 (on/off road).
Good luck!