"Fly by Wire" is a great thing, in theory.
(Especially for fighter aircraft).
In airliners it is for weight reduction and reducing labor costs (both in construction and during maintenance).
It can make an unstable aircraft perform safely. That is a good thing for fighters. Unstable = faster response and quicker turns. All the pilot has to do is point the stick where he wants to go and the computer will manipulate the flight controls to make it happen.
In practice it is only as good as the software logic that is used.
It is reported that the F16 would crash in less than 5 seconds without fly by wire.
The famous 1998 Paris Air Show Crash of an Airbus was caused by bad 'fly by wire' software.
http://www.airdisaster.com/investigatio ... f296.shtml
Airbus went to great lengths to blur that issue. They even substituted a the black box (flight data recorder) with a fake to conceal their culpability.
The pilot was doing a low 'fly by' down the runway so everyone could see the airplane in flight. In that crash the airplane had decided it was going to land, and ignored the pilots action of selecting go-around power. If the pilot had closed the throttles completely and then asked the airplane for power he would have gotten it. That is counter-intuitive, and proved to be a bad idea.
Composite use? Again, this is great for weight savings.
Weight savings is a BIG deal for airliners. In 1980 (when fuel was a lot cheaper than now) my airline had signs in the crew room reminding us that every extra pound of weight carried added thousands of dollars to fuel costs on an annualized basis. The point was that we should not be obese. The airline did their part by carrying fewer magazines, less beverages, less silverware, etc. Composites being lighter than conventional metals bring great weight reductions.
There are always risks with new technology. Remember the Aloha Air Lines Boeing 737 that shed part of its roof inflight?
http://www.time.com/time/magazine/artic ... 81,00.html
That was a failure of composite bonding (glue) techniques.
That airplane used bonding instead of conventional rivets to hold the aircraft skin (roof) on.
I would like to believe that aircraft engineers have accumulated enough experience that a repeat of that failure is unlikely.
Airbus planes are (historically) substantially cheaper than Boeings.
One of the reasons is that Airbus sold them below cost to get market penetration. They gave Eastern Airlines free A-300s back in the 80's.
Jet Blue got 3 Airbus aircraft for the price of one Boeing. This is fair trade?
Air Canada did a few dead stick landings (no engine power) of Airbuses for various design flaws.
The Canadian Ministry of Transportation imposed a gag order on their pilots to reduce the fallout of bad design.
The good news is that they made it down safely.
Airbus aircraft have a limited airframe lifetime (in terms of total flight hours). Boeing aircraft don't. This is because Boeings are built 'stouter' (also heavier).
Flying an Airbus (I have flown both Boeings and Airbuses) can be disconcerting due to the structural concepts that Airbus follows.
So many pilots (specifically the ones with lots of Boeing experience) just don't trust Airbus aircraft (or the company that builds them).