Many advantages, one is that you get to import a new key on the wallet, but if it is half node I think you cannot run another wallet (imported key) on it. Because an importing a wallet will need transaction history of that wallet and it might be that the few blocks there will not have all of them available.
In other words, it will only be useful for the wallet you currently have or that you create after having part of the node assembled. It even makes sense. If it is something older, it can no longer obtain all the transaction information.
But, if you think about it, the same thing will happen in a new wallet, if it only has part of the knot. Older transactions are no longer listed in the wallet. Or am I wrong?