My experience with it
I had a developer working (Visual Studio .NET) on a page that was a simple, tabular display of the results of a query. Basic Reporting 101. There was a parent/children relationship in the data, and the request was to group all children together, and leave a blank space after each group. After re-writing the page four times, changing the column layout twice, complaining that he couldn't do what I asked with late binding, re-writing it and changing the column layout again in order to remove the late binding, he still couldn't make it do what he wanted.
I'd have had the page done in about five minutes using any of a half-dozen freely-available frameworks, or two that I've done myself. If I wanted to do a one-off, I could have done it in a half-hour.
So while I'll admit it may be possible to do things with a data grid that are hard to do manually, I've gotten the impression it also makes it very hard to do some simple things, if the simple thing you want isn't one of the default behaviors.
Or I was working with a moron. That's always a possibility.
