JMHO, but Del-Ton will give you a reliable weapon.
Don't get hung up on brand names. Until you get into really exotic stuff, all AR's are built using pretty much the same parts, so you can spend lots of money if you really want to buy a fancy engraving on your mag well, or spend less and get the same rifle without the big name.
Personally I prefer iron sights and 20" barrels - an A2 in other words.
If you buy short barrels and funny length gas systems, etc, you can expect some degree of reliability issues. Guns ALWAYS work best in the size, caliber, and configuration as originally designed.