Also, after some additional research, I believe I have figured out the difference between the 229.3 and the 229.5 specs.

The 229.5 spec allows for extremely long oil change intervals (15k+) when used in conjunction with a fleece oil filter, and provides better fuel economy than 229.3 oils.

229.3 oils are good for up to 12k miles, or one year, and offer better engine protection for extreme engine demand situations (racing, towing, etc). That's why 5W-50 is only allowed in the 229.3 spec.

So, if you want better fuel economy, go with 229.5 spec oils.
If you want to race your engine, go with 229.3 oils.
If you want to go with extremely long oil change intervals, go with a fleece oil filter and 229.5 oils.
If you want a wider variety of oils to choose from at your local auto parts store, go with 229.3 oils.

BC.