Between the Black Diamond (which I own) and the Omega (which I will someday own) the Black Diamond is a pain in the you know what to clean. It takes me of all my rifles, the longest to clean. The Omega is supposed to be one of the easiest rifle to clean. I hasto be easier to clean the the Diamond.

What actually makes the Omega Z5 different from the standard Omega, I could not tell you. I have asked and all I can find is the sights are not the same quality as the standard Omega, and perhaps the stock is different. Perhaps someone else can comment on this.

It is a Thompson Center, which has the best customer service in the industry (at least one of the best). If you have a problem, they have a solution. Also the Omega is a known performer in its field. There are a lot of Omega owners on this board, and they do a lot of shooting with them.

Based on your circumstances of a Wal Mart purchase, and the fact you have concerns on the BPI barrel model rifles, this would be the best value for your dollar. This would be all the rifle you would ever need. And later if you mount a scope, you will probably hang up your centerfires like a lot of us have done.