I use Mindnode quite a bit, having moved to it when Novamind lost its way. Comparing Mindnode and Tinderbox is really like comparing chalk and cheese. Mindnode does one thing well, Tinderbox does many, many things. As is often said, Tinderbox is more like a toolbox.
I use Mindnode because the interaction experience with regard to keyboard shortcuts and formatting is very fast and fluid. I use it solely to create mind maps, unsurprisingly. 90 per cent of my use is to create speaking notes for seminars or lectures, which double as mnemonic aides for students during their revision. I speak from mind maps because it does not tie me to a linear route through material which means I can be more responsive to audience interest.
You can use Tinderbox to create mind maps. It is possible for these to be more visually expressive than any mind map software I’ve used. However, it is neither as fast nor as fluid as apps that solely do this sort of thing (I include, e.g., Scapple) in my experience. The increased scope for expressiveness is an asset, if you need it and are willing to increase the time to create the mind map. I have not needed it for mind maps.
Tinderbox, on the other hand, can do much more than just create a mind map. I would hesitate to try to describe all that it can do. It took me a long time to understand what Tinderbox is and can do. The main difference with a mind map in my use is that I create, store and use information in Tinderbox. Whereas I print my mind maps (first A4, then copied to A3) to use outside the software.
Tinderbox reminds me of HyperCard in its versatility and power–a comparison that may mean something to you depending on your vintage.