Overall, the Spidi Defender seems to be well thought out and well engineered. Heres some of the ups and downs of this rig.

Pros
Looks better in person than in the picture
Very comfortable
Will fit under your motorcycle jackets
Fits under regular jackets
Can be worn over plain clothes
Offers a good amount of coverage
Very quick and easy to put on and take off
Light weight
Doesn't hold in a lot of heat - would be ok for warmer weather
Fit is pretty much true to size but runs slightly big. I'm 6', ~180 pounds, ordered the largest size, and I have to pull it down as tight as it will go for it to fit and stay in place properly. I probably could have gotten away with one size down.

Cons
The biggest and just about only con is the price for what you get. I knew what I was getting when I ordered this, but after seeing it, I really have to ask how Spidi is able to charge three hundred dollars for this and actually sell it. You can buy the top of the line Spidi back protector for just over one hundred and the chest protector for about fifty bucks.... so is the harness itself and the ability to wear this vest standalone really worth one hundred plus dollars?
Even though I said it looks better in person, the only other con is - I look like an insect if I wear it over regular clothes.
I'd still rather *look* like an insect than *be* a squid.

Not crash tested.

Contrary to the others I am not as high on this product for several reasons. First off, I am 6'2" and I found the protector's length to be a bit too short. It didn't adequately reach and cover my tailbone.

Though it is a nicely designed and good looking piece of protection, it just didn't feel as though it would hold up to substantial impacts. The armor was plasticy, and didn't seem to provide the level of shock absorbtion that the Forcefield Pro Sub 4 did based on a simple "elbow me in the back" test. It was thin (which is nice to a certain extent), but not confidence inspiring. The breathability of it seemed to be an issue as well. I also noticed that it wasn't as broad along the top as the Pro Sub 4, so it didn't provide as much shoulder blade protection.

The one really strong point was that it is very comfortable in the suit and moves quite well with your spine's curvature. The straps seem well constructed too. All in all, I could recommend this to a street rider who doesn't ride in very hot climates. But I would not recommend this to a racer of track day enthusiast. Instead, those two types of riders would be better served in the Forcefield combo which I also reviewed.

Even though I had to send mine back I wanted to review the product in case it helps someone else. Overall this armor offers really decent chest and back protection and if you are a guy then this will probably fit nicely. For thin people like me (waist 28"), there's not enough Velcro on the sides (the straps are too long) so I couldn't cinch it tightly enough. I might have been able to modify the straps but there was a second problem - it didn't interface very well with a Leatt neck brace (two prongs in rear version). I found the prongs to align exactly at the edge of the back protector in a way that compromised fit of the neck brace. The size armor I tried was 5'3 - 5'7" version. The other thing to note is that it did feel hot to wear it even in the house while test fitting. Thankfully Revzilla made returning it painless.

I had recently purchased a mesh jacket which had hardly any back protection. I also use a textile 3/4 jacket which suffers from the same problem, The Spidi Defender allowed me to pull the skimpy pads from the jackets. Since broken ribs have been known to damage internal organs I welcomed the extra, frontal protection.

On a recent 4 day tour of California's central and southern coast, the Defender proved to be very comfortable, if a wee bit hot in the chest section. Spidi touts a ventilation feature in its advertising but I didn't notice much fresh air getting to the chest. It is possible to get some air behind the chest plate by hunching the shoulders every so often. In all fairness I should say that at present I could stand to lose a good 25 pounds. Perhaps it's the extra "padding" which interferes with the ventilation.

I would stress that the heat and humidity is only felt in the chest portion - not the back - and it's not terribly bad - it's just noticeable. I subtracted one star in the rating for this but I would have only taken off a half of a star if that would have been possible.

The back protector's fit and comfort was flawless. If a bit of chest sweat bothers you, you might consider a "back-only" protector. But if you're like me you'll feel a bit safer with the sternum and frontal rib cage protection the Defender affords.

I really appreciated the sizing options - There are 4 sizes available for people from 4'9" to 6'5". This assures a great fit, with the armor snugly following the curve of the lower back. I was happy to see that the "tail" of the back protector didn't stick out from under my riding jacket, which had been a problem with other protectors.

It's light weight, well made, and very comfortable. Buy it, wear it, and most of the time you will forget you even have it on.

I wanted a chest and back protector. This fit the bill exactly. My main reason for purchasing this over other options is because of the shoulder straps. They are simple straps, not bulky at all. This fits in perfectly with the rest of my setup, including a jacket with shoulder and elbow armor.

As far as protection goes, I honestly feel that this is extremely durable and strong. No issues at all with the material. It's going to take a lot to get through this.

Just two track days on it and no problems. For me, the rear protection should be longer for more coverage.

Very comfortable - you'll forget you have it on. Kudos to Spidi for making it available in four different sizes. Nice to find a protector that doesn't hang out the bottom of my riding jacket. Only small quibble is that in hot weather the chest can become a bit hot. Not a deal breaker however and easily overlooked when you consider the level of protection you're getting.

This chest and back protector is light weight, comfortable and fits under my jacket or suit with ease and you really don't realize that you are wearing it.

Having broken ribs from a crash, I never wanted to repeat that feeling. So this time around, I got the vest to not only replace my spine guard, but protect the chest as well.
It adds an extra step when gearing up, but those couple of minutes are worth the protection.

This armour fits very well, the construction seems to be of very high quality. It fits nice and snug but can ride up a touch in the back. I am 6'0 and the large fits well.

I can wear this all day and it is still comfortable. It is also vey low profile and discreet.