Initially though I found the extension hard to customise. While I am a PHP developer, I blame this on my relative lack of in-depth Joomla knowledge.
Any questions I had though were fairly promptly answered on the extendedreg forums. I was having a particular problem with an element of the extension and didn't seem to be able to get the help I needed on the forum. After this the developer skyped me personally and walked through fixing the problem until it was resolved and was very helpful in getting it fixed.
The developer said that in the next edition there would be a fix for the problem I was having.
I'm quite happy with this purchase and would consider buying other extensions from jvitals in the future.