Is there a real difference between the parts kit outside of the trigger and grip?
No, all lower parts kits are not the same. Quality and features can vary greatly between brands and even within brands.
When looking for a quality lower parts kit, it’s important to consider the following factors: reliable steel construction, proper fit and finish, a variety of features and accessories, compatibility with other components in your build, and customer service and support.
It’s also important to consider the price point. A good quality lower parts kit doesn’t have to break the bank, but you should be wary of extremely low-priced options that may sacrifice quality or features.
Check out this video on the AR15 parts differences: