The little tiger was much lighter and easy to ride, sweet engine and gearbox so better in traffic etc. But it lacked the go of the strom. They look the same style of bike but are much different. The tiger you have to rev hard, it only starts to go at 6000rpm, the strom is finished at that. They both had the same top speed, 125mph on the mountain mile but at real world the strom has much more grunt.
Worse thing about the tiger was the brakes, weak when two up and the harsh suspension, my wife hated it. Mine was a road model the xc is better but I'm not riding around on tubed tyres no more, its not the 70's anymore!
The tiger's an OK bike but the price is to much for what you get in my opinion. I had some warranty issues and they and our only triumph dealer here just laughed at me.
Take a good long ride on the strom, try it in all situations, motorway, traffic etc. And shop for better ear plugs for the rattles!