Every engagement model has its own merits and demerits. There cannot be 'one for all' kind of model fitting all your projects and requirements. The applicability of any model depends on lot of factors. These factors need to be considered, discussed, analyzed and then the model fitting ~80-90% of the requirements should be finalized. Yes, there will not be a single model that will fit 100% to all your requirements or to the different scenarios in the project scope, at least have not seen one yet. This paper highlights and discusses these important factors.
