We're pleased to work with Kendo UI. Its design is good, however we find here and there things we would wish be done better. Here is a list of problems in a no particular order we would like to be addressed in the next release:

• RTL is not supported (including correct scroll bar position see Tunning KendoUI).
• Templates and binding should support a context information along with the data source. (Why do they use with statement?)
• attr binding should use jquery.attr() method; there should be prop binding which is analogous to attr binding.
• There should be custom binding that allows any json object to bind to different aspects of a widget or an element.
• One should be able to use format/parse functions during binding. (Allow binding to express as a triple json object?)
• parseExact(value, format, culture) method should be rewritten, as it has nothing in common with parsing data string according to exact format.
• Type inference during binding is poor (parseOption() method). It works neither for string "1,2", nor json " { x: 0 } ", nor for date.
• Binding is not implemented for many components: splitter, grid.
• Splitter's pane should support size="auto".
• Drid does not support totals in group headers, nor it supports header selection.
• DataSource does not works after remote error, neither it allows to cancel request.
• innerHtml is used all over the code, thus one cannot rely on jquery.data().
• Grid does not support customization (localization) of a column filter.
• Grid should support data binding of its content.
• One should be able to destroy any widget.