Advantages:
He will own half your property, therefore this will be taken into account should you need to fund care home services.
It will avoid some potential Inheritance Tax depending on the value of the property and if you live more than 7 years after the gift.
If he becomes joint landlord with you it will lower your income from the rent for your tax purposes.
Disadvantages
If he declares the gift he may have to pay Capital Gains Tax
If he becomes joint landlord he will have to declare the extra income.
If he is married and dies before you his wife will automatically inherit his half of your property unless he Will it or creates a caveat on the Deeds
Personally I would not hesitate to put him on the Deeds, but consult a solicitor as the best way to do it.
https://www.moneyadviceservice.org.uk/en/articles/gifts-and-exemptions-from-inheritance-tax#how-much-can-i-give-to-my-children-and-family-tax-free