Any downsides to switching at 1000 miles vs. later on down the road?

I would wait one more change and let it break-in some more.

I would wait one more change and let it break-in some more.At least one more change would be better, could wait till second change too...

Any downsides to switching at 1000 miles vs. later on down the road?You're changing oil at 1000 mi?

I changed mine to synthetic after 3000 miles, and it seems to be working fine.

Any downsides to switching at 1000 miles vs. later on down the road?

Why at 1000? If you wait until 3000 then switching is ok. If you need to change before 3000 I would use the GM break in oil.

Any downsides to switching at 1000 miles vs. later on down the road?

There's no downside as far as the engine. But I would get through your break in period then make the switch (Like everyone else is telling you) Since synthetics have a extended drain interval.

There is no "break in oil" it’s just a dino oil. You should do an early change to make sure you get any crap from the factory out of the motor by 3k at most IMO then switch over to a syn when your DIC tells you too.