Way up the situation and wear what you feel suits your situation and mindset at the time.
On busy wet british roads I'm happy in my leather trousers and waxed cotton jacket, never had the inserted protection and never will as I find it uncomfortable and restrictive. I have many years of experience and feel I no longer ride to the limit so am confident in my chances.
When in rural Spain I have travelled in shorts and t shirt but always army boots and gloves(my mam said I always had to wear these cos she aint gonna wipe my butt) but you can see for miles, no traffic and taking it easy all adds to the experience.
When it comes to the BA brigade whether wearing t shirt or full leathers when they have an accident they are dead, the leathers just makes the end package a little bit tidier.
Mark