I have probably tried all the iPad mind map products and, for me, iThoughtsHD is the best product.
Even so it does frustrate me sometimes. one example is that i like each topic to be a difefrent colour or range of colours. There may be away of getting iThoughtsHD to remember the "Rainbow" setting, but I have not found it. I also find thatv the colours tend to be quite similar.
Things I love about it are being bale to get to the start of a phrase in one of the boxes, or to the end simply and quickly. I wish I could attach files to a box as well. The box would show a paperclip on one corner of the box. Clicking on the paperclip would load a menu which would list the attachments and allow me to open the attachments.
I have a few other suggestions, but those would do for a start.
It is a good product.