We are using a bunch of server controls of every flavor that mimic all the standard controls and then some (all the way down to a control that emits Header HTML tags and horizontal lines). Deep down, they inherit from WebControl but fully render the HTML, rather than inheriting from Textbox, etc. They do not use Control Adapters and hand wrote the browser configuration stuff.
Over the years the controls have been tweaked, especially controls like the DataGrid, to the point that it becomes an issue to remember all of the settings (especially for a newbie like me). There are special Javascript hacks that have been built into them to solve particular problems. Management is getting to the point of getting irritated that it takes longer to code with them and the tweaking involved to handle special cases. In some cases it seems that we are (or already have) painting ourselves into a corner.
This has especially become an issue since we have started doing a strict conversion in prep for HTML5 and to make the app work with more browsers. The question is: has anyone ran into a similar predicament and what did you do to solve this issue? COTS controls, keep doing hand coding of the special server controls? In talking with my coworkers, there seems to be a disdain for the standard controls and how they emit HTML, but switching to a different framework (i.e. MVC) would be very problematic, being the codebase is so large.