"Has anyone used Impression Pub before but now uses E/TechWriter?"
Lots of people, including myself.
"How did you find the change adapting to E/TechWriter."
Well, for preparing simple letters, etc., it's not dissimilar to any other word-processor, and I got going straight away.
Once I decided that I wanted to use it more effectively, then there was a bit of a learning curve. After reading bits of the Manual and working through the tutorials (all well-written), the structured approach gradually began to make sense. The EasiWriter discussion group is full of helpful souls too, which is a great resource to have when making the transition.
Nowadays, when going back to Impression (as I very occasionally do when I need a frame-based approach), I really miss EasiWriter's structured approach to documents.
"I think I just need to spend more time with E/Techwriter learning how to use it?"
Even if you don't have the time for that, it's well worth getting an up-to-date copy as Word import/export has received a lot of enhancement.
"It appears to have most worthy features."
Indeed! One of my personal favourites is "Save as Draw". Equation-editing is, arguably, second to none.