Follow W3C standards for http status codes. For instance if a published REST service doesn't receive a required input parameter, TDV currently returns a status code of 500, which is incorrect - it should return 412 or 422.
The inability to send the correct http status code is preventing customers from using TDV web services, causing them to write their own web services. TDV can deploy web services in less than have the time, but the faulty status codes cause havoc in customer development methods.