[gschier]

I covered this a little bit in the comments below, but one of the reasons I created Insomnia was because I found other tools (including Postman) to be hard to learn and use. So, for me, the main advantage is having a clean and simple (but still powerful) interface. Insomnia also has a Linux desktop app, which makes it one of the only REST clients to support all three major platforms.

Insomnia is still in early stages, so if you have any feedback or suggestions I'd love to hear!