A tenant always prefers an SNDA so that if the landlord's lender forecloses, the lender will have to respect the tenant's lease. But if the landlord files bankruptcy, or if the lender causes the landlord to file bankruptcy, the landlord can reject the tenant's lease anyway thereby subjecting the tenant to the very risk it was seeking to avoid.
In a currently ongoing bankruptcy case, the bankruptcy trustee went so far as to demand the tenant to move out immediately because the trustee was shutting off utilities to save money for the estate. In most cases, the lender does not want to avoid the lease because it wants the rental income. For the same reason, the trustee usually does not want to reject the lease.
The real risk is where the property is to be redeveloped for a completely different use or is being held by a non-operator who wants no responsibility for operations whatsoever. In both cases, an SNDA may not suffice given the remedies available in bankruptcy.