I have been unable to make a definitive choice and was hoping that somebody (or a combination of a couple of people) could point out the differences between using RestSharp versus ServiceStack's client services (keeping in mind that I am already using ServiceStack for my service). Here is what I have so far (differences only). The list is fairly small as they are indeed very similar:

ServiceStack

Pros

• Fluent Validation from my already created service POCO objects
• One API for both client and service
• Code reads better (i.e. Get<>(), Post<>())

Cons

• Some of my strings must be written out (i.e. If I make a GET request with query parameters, I must create that string in my code)
• I must create a different class for each Request/Response Type (JsonServiceClient, XmlServiceClient)

RestSharp

Pros

• Just about everything can be a POCO (i.e. If I make a GET request with query parameters, I just add the parameters via code)
• Switching between Request/Response types is simple (request.RequestFormat = DataFormat.Json/Xml)

Cons

• Manual Validation (beyond that found in the Data Annotations)
• Two APIs to learn (this is minor since they are both fairly simple)
• Code is not as readable at a glance (barely) (i.e. request.Method = Get/Post.. and main call is Execute< T >())

I was leaning towards RestSharp since it tends more towards straight POCO use and very little string manipulation, however I think ServiceStack might be acceptable to gain the validation and code that is more easily read.

So, here are the questions:

• Which do you prefer?
• Why the one over the other?

I know this is not a totally subjective question, but at bare minimum I am looking for the answer to this question (which is subjective):

• Are any o