If you have longer form Notes on contacts and have noticed that they are shorter than usual in FullContact, it may be related to this issue if you are using Plaxo as well.
It turns out that Plaxo is restricting the Notes field in a contact to 2K (2,048 characters) length. Anything longer is cut off with no warning message. So this is a Plaxo design restriction, NOT a gmail restriction.
However, if you are not using Plaxo and still have issues with shortened Notes on your contacts, please email us at support.