with full synth - I have seen that the oil doesnt stick too well to surfaces and drips off overnight, causing worse rattly start. The oil capacity is pretty piss poor too on them so I think its better to use a cheapo dino juice and change earlier. E.g. my car gets an 8000 kms oil change on cheapo stuff with needing to add a litre after 5000 kms.
I can use a stout full synth oil and go to 10,000 kms - but my cost doubles for just an additional 2000 kms (not economical) - I dont think it makes sense where I live. If I were living in the frigid tundra like somewhere in Alberta Canada - I would no doubt use a full synthetic oil as without it the engine would refuse to start.
The newer toyota engines with 0W16 engine oil have larger sumps and a higher volume and variable oil pump. They are not in the above category.