Regarding one of the drawbacks to joint trusts in a non-community or separate property state:

Loss of Creditor Protection

All of the assets of both spouses may become subject to the claims of creditors of just one spouse. In addition, all of the assets of both spouses may become subject to the environmental liabilities of just one spouse’s separate property. These results can usually be avoided if separate trusts are used.

Louis S. Harrison, “Marriage is Joint; Why Not Your Trusts? When to Use a Joint Trust As a Passthrough Entity in a Separate Property Jurisdiction,” Journal of Passthrough Entities, May-June 2005.