So, I've been using streamr extensively for the past couple of days to transcribe and translate (from English to Turkish) a 30 minute file that has heavy specialized terminology (neuroscience, psychology) with complex sentences. I have to say streamr WORKS GREAT and is a huge time saver for my video subtitling.
The initial setup (getting google cloud API keys) may look initially scary but they have a detailed step by step video that takes you through the whole process and makes it easy to get your API keys and take advantage of the google generous $300 bonus offer. For when my free credit runs out, google cloud pricing is very cheap for the service they provide.

The support is very friendly and responsive They were kind enough to create additional accounts for my 3 team members so we can work in parallel translating and subtitling videos.

The software is easy to use and very simple to work with. Google transcription API was about 70% accurate and the translation API was surprisingly accurate for english to Turkish conversion.

Things that could be better (and if improved could make streamr a top world class subtitling application):

- Subtitle formatting (I'd like my subtitles centered, currently they are left aligned)
- Start / Stop the playback using the spacebar (now I have to mouse-click the play button)
- Importing (already made) subtitles. I have some ready accurate subtitles I'd like to translate. For the time being I can't import my existing subtitles to a project.
- Drag / Pan the time line using the mouse. For now I have to use a scroll bar to navigate the timeline for longer videos.
- Adjusting the time length of the subtitles by using the timeline. I can move the subtitles left and right in the timeline to precisely position them, but I can't change the start/stop or length from the timeline.
- Exporting a project to share with team members. I couldn't find a way to export a project to send to a team mate to continue where I left of on his copy of the application.

If any of my suggestions/requests above gets implemented streamer is going to be even more amazing!

The application works great as it is and I'm very happy with my purchase. I recommend streamr to anyone working with subtitle translation on mac or pc.