I migrated my 50.6 YAMv2 to roughly 222.8 YAMv3. The same amount of YAMv2 would have gotten me 397 YAMv3 if swapped on uniswap.
So if you don’t have a lot of old YAMs to migrate, might be worth checking Uniswap first before doing it over the yam.finance website.
EDIT: I also have around 79 YAMs vested, which I forgot to add. Still, the Uniswap route would have been better.