On a 1080Ti (so a 6 year old GPU), the large model runs in 1x time (so transcribing 10 minutes takes 10 minutes) and I've successfully transcribed even 1h+ files.
We're still very early stage and stealth so it's not quite clear to us where our lines are with regards to special sauce/significant competitive advantage.
As the CTO (and lead dev) I'd lean towards open sourcing it (because it's awesome and we're standing on the shoulders of open source giants already) but it may become clear it's too differentiating to open source. As I said it's just too early to tell.
What I can say is if we open source it HN will be the first to hear about it!