Those who want/use armor in summer riding gear are well aware of the two major problems with recent approaches to armor.
The first is that most jacket makers simply don't provide any useful back armor (and often, no shoulder or elbow armor either) so you have to purchase it separately.
RevIt, First Gear and others simply use EVA foam backpads which are nearly worthless. This same foam is also used as hip and knee pads by various pants makers and is commonly seen as shoulder and elbow "armor".
The second is that much recent armor fits badly in gear makers pockets (eg knee pockets on Sliders kevlar jeans are poorly designed to hold even their own optional armor in place) and is hard edged and/or non venting in summer weather (eg Knox shoulder and knee armor, SAStec back armor etc etc) so is major league uncomfortable in hot conditions.

This summer season, for the first time, there is a good selection of flexible, venting, trimmable (to make retrofit easier) most importantly CE rated protection armor. It is now possible to have comfortable and vented armor in summer gear and few excuses not to.

My candidates of choice for various Street applications (racing applications can call for other types) include vented D3O pads, Forcefield multlayer items (especially their unbound backpads which can be bought in sizes and trimmed to fit almost anything) and RevIt's new multilayer backpads. A large selection of these can be seen on the Revzilla website.

Among the upgrades I have done this spring
1) Replacing a SAStec backpad that was too stiff and hot in my RevIt Tornado jacket with a Forcefield CE1 size 002
2) Replacing the EVA foam is the SOs First Gear mesh jacket with a D3O size A that I trimmed to fit
3) Replacing EVA foam hip pads in RevIt and First Gear pants with rated D3O or First Gear armor
4) Putting trimmed D30 knee armor in kevlar jeans pockets
5) Replacing all of the foam pads in my leather jacket with rated armor- back, shoulder and elbow- mix of D30 and Forcefield used.

Where they fit existing pockets, Forcefield tape trimmed pads remove the uncomfortable hard edges of, for example, Knox pads while proving better venting. Where pads need to be trimmed to fit, the D3O, unbound Forcefield or RevIt pads would be a better choice- all of those can be trimmed with a sharp knife or strong scissors.

So far, the SO and I are fortunate enough to have never seriously tested our gear- but we're also getting older and more fragile. Gear upgrades to current technology are part of our program to extend riding years in comfort as long as possible. Every few years it seems one gear category or another makes a significant leap so we have periodic upgrades as old, worn or obsolete gear gets replaced. Comparing what I wear today to what existed when I learned to ride in the 1960s is almost laughable due to the huge number of gear improvements.

Of course, no amount of armor can protect you from an 80 mph impact with a roadside oak. But any person who has spent enough time at tracks has seem plenty of evidence of the potential of modern gear to greatly reduce or prevent injury in typical offs...

What do you use that could stand an armor upgrade for your comfort and safety??