It would depend on your circumstances; ie do you want the estate to remain in proprietary possession of your family for ever? As I understand leasehold (With the exception of renting) it will revert ownership after the specified number of years is up (Say 999 years). Legally, under the LoP Act 1925, you are not actually 'buying' your house.
I think you need to think of the resale of the property. Unfortunately more and more people these days will only consider purchasing freehold properties as it means they own the property out right.
Why is is legally better as a leasehold? I bought the freehold on my flat as the freeholder decided to put it up for auction. As the owners of the flats, me and my neighbour had first refusal and we bought it jointly to prevent certain firms in my area buying it and then trying to get as much money as possible out of the leaseholders. If you have any issue with them you have to declare it when you sell the property which could be a problem. When I came to sell the flat it was definitely a benefit that the flat was sold with a share of the freehold. It was beneficial to me!
i bought my house in may this year.it was to be sold as leasehold but the freehold title was available if i wished which i bought.i enquired about the leashold to my solicitor and was told that if i wanted to make any structural alterations to my house and it was leashold i would have to contact the holder of the lease to ask his permision as he owned the land.if there is a long lease left the ground rent will be small but dramatically increases as the time goes on.hope this helps you.
Under English law, you can't impose covenants on the use of a property unless it is on the ground. So if you have one flat on top of the other, neither flat will be responsible to the other for anything. The one on the top must maintain their part or the rain comes in. The one on the bottom must be maintained or the whole lot will fall down. The only way you can impose joint covenants is by creating a lease and making the lease conditional on those covenants.