Life interest or discretionary Trust following an IPDI?

I would welcome views upon whether, upon the death of a surviving spouse who had enjoyed an IPDI, it would be better to have a succesive life interest trust for children OR a discretionary trust. Both would be Relevant Property Trusts and both deemed to be established by deceased surviving spouse I believe. The intention is to seek to provide asset sheltering against a beneficary’s spouse and creditor and possibly care home fees. (I appreciate that if we want to use the Residence Nil-Rate Band we would have to alter the trusts provisions during the lifetime of the surviving spouse so the children inherit the house absolutely - but that power can be included in the Will and I think the nature of the follow on trust is irrelevant here). So, is there a good reason to end up with a life interest trust or a discretionary trusts? Assuming the Life interest trust would have overriding powers of appointment, trustees of both could exercise powers to appoint income to say grandchildren to reduce Income Tax. A discretionary trust would offer greater potential asset sheltering. i cannot se why one would ever prefer a succesive life imterest trust…am i missing something please?

Shaun Freeman
Freemans solicitors