Hi Eric,
Although there are some issues, I am still a fan of Infragistics controls in combination with LLBLGen Pro (in winforms scenario's). I am currently working with Infragistics version 2005 / 3 in an Adapter scenario.
The way to work is just to slap an EntityCollection component on your form and bind the UltraGrid to it. All properties are recognized, even custom ones that you add to the Entity classes yourself.
Related EntityCollections are shown as childbands. Mind you that this only goes one level deep at the moment, due to Design Time binding issues.
The ListObject property of an UltraGridRow provides easy access to the underlying EntityCollection.
At runtime you can point the grid's datasource to a different EntityCollection and call DataBind(). All column settings are retained.
Binding to TypedViews and TypedList is just about as easy.
Because I have been using Infragistics for the past few years it is possible that I'm a little blind for other vendors but I still think Infragistics NetAdvantage gives alot of bang for your buck. For the record, I don't get any commission for promoting Infragistics
I am not sure about the Excel style drag/drop you talk about. I do know there is support for drag/drop through the whole NetAdvantage Winforms framework.
Just my free advice, be sure to decide based on your own judgement.
Kind regards,
Ries