“Having some armour” isn’t really a good enough statement...
There’s good armour and rubbish armour.
And there good leather and rubbish leather.
And there’s good manufacturing and rubbish manufacturing.
And there’s good fit, and rubbish fit. This is even more important with armour, that top of the range elbow armour won’t help if it’s sitting over your forearm, or if it slips around the front during a crash, etc.
A well made, good fitting leather will afford far more protection than a poorly made and poorly fitted ‘armoured’ jacket.
I have a MTM jacket by Crowtree (no longer in business). I had it altered recently by Hideout Leathers, I explained to them that I tend to find armour uncomfortable, and the net result is often that the armoured jacket gets left on the hanger whilst I choose and ‘old faithful’ for rides.
Hideouts comment on the Crowtree jacket were that even if I removed all of the armour, it would still give better protection than 99.9% of the off the peg offerings available.
It’s not my choice, but an option is to wear an under jacket armoured ‘shirt’ and a good leather over the top. This gives the option of wearing armour or not, even with the same jacket. It is also a good way of ensuring the armour is held in the right places.
Finally, leathers that are too stiff will effect comfort AND safety. They can lead to reduced glances over the shoulder and / or reduced control, meaning, they can be less safe. Also, a suit that is too stiff is bad in a crash as it moves most of the ‘stress’ to the extremities, ie wrist, ankles and worst of all, neck! A good suit needs to let you ‘roll with the punches’ so to speak.
My Crowtree Road kit is of quite thick leather, this gives some impact protection and the thickness gives very good abrasion resistance, but it took a lot of breaking in. My race kit is of thinner, far more supple leather, but has top notch armour, and a Kevlar layer on the inside in the important abrasion areas. This obviously provides the best balance of comfort and protection, but I seldom wear them on the road.
Just some more food for thought...