Here are few of the commonly raised questions on WCF over ASMX. Let’s quickly review them:
1) Should WCF be considered a superset of ASMX web services?
2) Is there any reason to still write new web services using ASMX instead of WCF?
Technically, I cannot think of any reason. But yes, if some team that knows asmx but not wcf, or have a project with a lot of asmx services and you do not want to introduce a new technology.
3) Does WCF provide better facilities for working with SOAP messages, as opposed to SOAP Extensions?
WCF has message contracts.
4) Can I restrict communication to SOAP 1.1 using WCF, the way I can with a web.config change in ASMX?
Yes, basic http binding
5) Does WCF have an easy way to log or review the requests that hit the service without resorting to something like SOAP extensions?
Yes, we can use WCF tracing