the X1 is supposed to be excellent.
Personally i dont use anything, mainly as i dont really leave my bike anywhere where theft is a big risk. There is underground secure parking at work and when i use it for pleasure i am generally riding it or in a cafe car park. At hoome it is in my back garden locked in a metal shed, very few people will even know i own a bike. Plus its not a hugely desirable bike, street triples are 2 a penny.
I am going on a trip in May to the Italian Alps but we are only booking hotels with secure parking.