Even if some browsers don't correctly implement some MP functionalities, they accept the xhtml mp. So there is no real reason not using MP.
But the question you should work on is more which functionalities (I mean by functionalities Xhtml mp/WTAI/WCSS/... combinations) among the great number of theoretical possibilities you can use.
Because of actual and future browser lacks it s not easy to find a way to create a site that could be well seen by a maximum of users. You may choose one of those solutions:
- To build a wap site using functionalities that work on all (or a maximum of browsers.
- To conceive several versions of your site adapted to some precise groups of devices that have globally the same characteristics.
The key is to find the good balance between richness of functionalities you can use and costs of development due to the number of versions of the site.
What s in all cases important is to know well what browsers can and can t do. And that s not simple...
If you send me the URL, I ll be happy to see your site.