I’m considering buying a .223/5.56. My local hardware store has the Core 15 M4 Scout including hard case and 30 round magazine on sale for $550. What is your opinion of this rifle vs. the S&W M&P-15 Sport?
For casual use, either would likely be fine. At that price point, I think the M&P Sport is a much more known and proven rifle.
For harder use, I suggest stepping up to a Colt, BCM or Daniel Defense. Given that right now you can get Colt 6920s for $850, if you can swing the price difference compared to the S&W or Core, to me it's a no-brainer.
But as far as entry-level ARs go, the Sport is the one to beat.
S&W well known, major manufacturer, with a long business history that has the financial resources to back their warranty and properly staff customer support and repair services.
Core is who? I think I remember some small shop all of a sudden put ads in various gun rags and on the internet a couple years ago. That's about all I know.
An AR is an AR. Depends on whether you prefer to impress your friends or save some money. It also depends on what features you like. I'd suggest buying a stripped receiver, and shopping the web for the exact parts you want, and put one together yourself.
A good trigger, good barrel, and to some extent, a good bolt control group are what to spend money on. The rest is just window dressing.