just my 2 cents from my recovery point of view ....
If I had to select one of your 3 options I would definetely stick to what you use now.
In my experience NTFS is the best choice when you look for a reliable filesystem that can survive power failures and other problems.
Do not use VMDKs as large as 27 TB - and if you really must use such extralarge vmdks create them as eager zeroed thick and write down the mapping after creation.
Otherwise beware of power failures - one incident and your 27TB may be gone ...