xamDataGrid, NetAdvantage For WPF

I have been using the Beta version of Infragistics WPF toolkit for a couple of months now and have given it some slack but I am somewhat disapointed with the recent production release in a number of areas;

1. Peformance is bad, really bad, to the point where I can not justify using this for a major project that I am working on, and am seriously looking for an alternative, Xceed comes to mind.

2. There appears to be no ability to generate Summary rows in the xamDataGrid, this for many users is a very important feature, and I use it frequently for financial reports that  I need to generate for the client.  It is interesting that there is a Header concept but no equivalent Footer concept, BTW Exceed has this!

3. Did I mention that performance is bad !!!!!, this really is the show stopper as far as I am concerned.

I am willing to give this toolkit a chance, but the above issues need to be addressed soon, otherwise I have to find an alternative.