We have products that are one time products and subscription products.  

1) We would like to have the ability to create an opportunity in CRM that includes both one-time charge products and subscription products.  Currently the only way of creating a subscription product is by defining a "Product->Plan" hierarchy in Zoho Subscription.  It appears that the only SYNC between Subscription and CRM is around contacts and the Product->Plan hierarchy doesn't sync to CRM, thus, you would need a duplicate copy created in CRM for the purposes of being able to use it in an opportunity.

2) The "Product->Plan" hierarchy does not map into Items in books.   i.e., when a customer is charged on a subscription bases, there is no way to get reports in Books that would be sales by Items.    The charge is simply synced to Books as an invoice with a description.  (Product and Plans needs map to items in Books).

Perhaps I am missing something here, but I would assume our use case is very common.