The good
New plasteel baricades.
Beside the fact that they're fancy AF, their new functions are really good. You can not only use them as doors, but they also can be MOVED AROUND! And, unlike fake walls, crushers cant breach them in 1 charge. That, in my opinion, might be very helpful against crushers during assaults. The only drawback is that you have to pull each baricade just like a sentry gun. I'd like to see them being more easy to transport, similiar to roller beds.
Barbed wire.
Prevents runners from running past your baricades, makes aliens take damage. Doesnt need to be explained, i think. N e a t.
Metal baricades.
Finally we got a durable enough baricade that can be built from regular metal! That means you can make something as tough as sandbags, even during a fight on almayer.
The bad
Since the fake walls are now gone and replaced by plasteel baricades, engineers will probably have some problems with the ammount of doors they can build. Each still gets 6 plasteel baricades by default, which is not enough in my opinion and will make engineers lifes harder, especially during lowpop and midpop, because they're now more cargo-dependant. Giving squad engies more plasteel and making plasteel cheaper to order is something i'd like to see.
Another problem is the lack of some cheap defence structure that will help to keep xenos away from your baricades. Yes, a replacement for racks would be a nice thing.
The ugly

Like c'mon. Fake walls are gone, we dont need such a change. Makes engies rely on cargo even more. Walls are still needed to block areas that you cant watch all the time and crushers can still destroy them very fast.
Well, post your thoughts.