On the REST part it is not ideal for complex object based system where there are multiple resources which have n number of relationships and different http verb

On the REST part it is not ideal for complex object based system where there are multiple resources which have n number of relationships and different http verbs on them can be mean different operations when exposed in a different way. ( I know its confusing.. :)). I just look at it as a design pattern which makes client side devs consume your services easily. It definitely helps in creating simple webservices but REST as a whole I would say doesn't satisfy everything a backend developer would want to expose or do in an efficient way. Think of batching... in REST.