Among all types, they seem to be the one who always appear to be doing the right things at the right time and they know how to present themselves favorably. I'm usually impressed by them until an ISFj friend pointed it out to me that another way of seeing them is that they are too perfect to be true, to the extent that they appear rather fake and seem to lack their own personality because they are always saying or doing the right things. They are too concerned about building a professional facade of themselves and I find it hard to know who they are as a person until I'm in their special circle. I find them rather hard to type as a result.