Hello,

 When working with the NetAdvantage controls for ASP.Net, I would like to recommend some of the ways that I address the issues that you are facing:

•  AJAX and Client Side programming
  • The NetAdvantage online Help (Accessible through http://www.infragistics.com/support/documentation.aspx#OnlineDocumentation) contains  a Client Side Object Model reference guide that lists each of the ASP.NET Controls as well as the Methods, Events and Client Side Object Model that can be accessed by using JavaScript code. In this guide, you can review the controls that you are using and see if there are any client side methods that you can leverage.
  • If you are using the WebAsyncRefreshPanel, you will note that the "refresh()" method will allow you to force an Ajax postback:  http://help.infragistics.com/Help/NetAdvantage/NET/2008.1/CLR2.0/html/WebAsyncRefreshPanel_Object_CSOM.html 
  • If you are using WebGrid, you will notice that you can use the "InvokeXmlHttpRequest( )" method to force the WebGrid to perform an Ajax request as well: http://help.infragistics.com/Help/NetAdvantage/NET/2008.1/CLR2.0/html/WebGrid_Object_CSOM.html.
• Styling and Reusability
  • My recommendation on styling your application would be to use the Application Styling framework that was designed and built directly into the NetAdvantage controls. To learn more about this, the following topics should answer any questions: http://help.infragistics.com/Help/NetAdvantage/NET/2008.1/CLR2.0/html/Web_Application_Styling_Framework_ASF.html
  • Presets are more geared towards functionality based property settings rather than styling. It is true that Presets can be set up for Styling however, with the advent of Application Styling, the Preset is now more suited for functionality based reusability. Application Styling is a great way to style ALL the NetAdvantage controls within your Web Application. Presets work on a control-by-control basis. Presets are great for providing a reusable asset related to specific functionality. For example, if i spend time customizing the WebGrid so that it has OutlookGroupBy, Deleting is disabled, Updating is enabled and many many more property settings, I can create a preset called "Tom's Preset". This preset will be created with the option to only contain functionality based property settings. This preset can then be handed off to other developers so that when they throw a new WebGrid onto the WebForm, rather than spending time setting the same properties, they can just load "Tom's Preset" and be done. The following topic will explain Presets in more detail: http://help.infragistics.com/Help/NetAdvantage/NET/2008.1/CLR2.0/html/Web_Working_with_Presets.html
• User Controls / Master pages
  • These are supported, however, if you happen to encounter any problems, please make sure you submit your issues to Developer Support as they will be more than happy to assist you and make sure that you are successful.
• General Tips
  • To code or not to code: Whenever working with new controls, I make sure to spend time in that particular control's topic pages. To get to the control topics in the Developer's Guide, simply follow the table of contents: ASP.NET / Developer's Guide / The Toolset / Controls and Components / WebGrid. Here you will find an "Understanding" series of topics which when read, will acclimate you to the control's features and functionalities which will then give you a good idea on what you can do with it and why. "Getting Started" shows you how to perform some tasks such as using the Designer, creating the WebGrid through Code and several other quick start topics.
  • Overall, the help should address most of your inquiries. Anytime you encounter any issues that are not covered in the Help, you can always get in touch with our Developer Support department. If there is content that is not in the help and you would like to see it added, you can always use the convenient links located at the bottom of every Help Topic page (towards the bottom, where it says "Email your feedback on this topic") as we are always receiving and reviewing requests and adding the ones that address reasonable issues.

 Hope this information helps. Thanks and take care!

Tom