How is the quality?

I want an O/U for all-around shooting, small game, and very, very informal clays.

I know the CZ crew very, very well.  Great bunch of guys in their shotgun division.  I have been a critic of CZ quality in the past, but the recent turns within their shotguns have changed my mind.

CZs are manufactured by Huglu.  I must admit the the quality control of their earlier offerings from years ago could be spotty, but Dave Miller and his staff have done a lot to improve things.  They have top-tier customer service, and will do all everything possible to make things right if you encounter problems.  I know one customer personally who had a problem with the barrels on his CZ O/U, and Dave himself got involved to ensure that the appropriate repairs were made (and at significant expense to CZ).

my wife is a small statured shooter and she fell in love with a 20ga Redhead Premier Reduced length.    I did a ton of research  to make sure it was something that would last for the sporting clays we do regularly and I was impressed with what people were saying.
Once we got the gun, we went over it top to bottom and I am really impressed with the build quality.  It does not lock up like a vault door, but it is solid.  Easy to clean.  Fit and finish is fantastic.  No burrs or obvious corners cut.  
I am a B gun fan and CZ has really impressed me.  I would not hesitate to buy another one.

Ran a 20 gauge CZ o/u for a number of years.  Canvasback I think was the model.  Ran great, never had any issues whatsoever.

They still haven't fixed their soft metal problems.

OP will be fine with a CZ given his needs though.  Just don't buy one expecting it to last as long as a SKB, Miroku, Browning, or Beretta in terms of round count.