Hi @dyngts,
I’m one of the developers of torchbearer. Probably not qualified to talk about TNT or Ignite too much but I can give an overview. As I understand it, Ignite is predominantly a replacement of TNT, hence the similarity between them. Ignite is particularly useful if you have a large amount of non-standard code but still want some of the support offered by a training library. Torchbearer  makes a few more assumptions about your training process, but uses these to offer more features out of the box (like visdom and tensorboard logging, checkpointing, etc.). So for particularly complex constructions, ignite is probably a better fit but can require a lot of code. For simpler problems, torchbearer can get things moving a bit easier / quicker. For a compaison and some links to other similar libraries have a look at our README: https://github.com/ecs-vlc/torchbearer 64. Obviously my opinion is biased so it’s probably still worth trying out both to be sure.
Thanks!