Update:
I thought I would try to use some USB devices. I installed mupen64plus and plugged in my joystick to the right hand USB port. All working. I plugged my hub into the left side, and powered the hub. The gemini wouldn't charge, but that is the same as android. I plugged my 3tb harddrive into the powered hub, and no problems. Sailfish can see the drive, and it is being powered by the hub. So, USB seems to be a go on Sailfish.
Battery:
I have been hitting sailfish pretty hard, and I reckon it will last somewhere between 8-10 hours continuous use. That is in the same ballpark as android. I haven't checked things like standby, as it hasn't been idle Gut reaction is that it uses slightly more juice than android, but it is a full linux system, with proper backgrounded processes so I can live with that.
Browser wierdness
Ok, this took a little while to work out, as I am not a sailfish guru. When I look at oesf.org, the browser zooms in to the page and you can't scroll. After a lot of trying to pinch zoom in and out, it turns out that you can double click a component to zoom in, and double click to zoom out. By double clicking, you can get the screen back to full view. I am sure this is some sore of helper functionality, but it can be annoying. The only page so far that it is an issue is oesf.....go figure.
X25 vs x27?
I run one of the original x25 units, and have been trouble free in installation and running. I don't know if the people who are having problems are all x27, but maybe the dual sim thing is causing problems. If the sailfish port has been on the cards for a while, it may have been developed on an x25. I didn't think there was much different between them, but........
Keyboard
Just thought I'd mention that I had no issues whatsoever with the keyboard. I have a US keyboard, and perhaps that is the sailfish default, or maybe the country selection set the keyboard. All keys are working correctly straight out of the box.
Overall
I am liking sailfish more and more. It seems a really good fit for the gemini. A few hotkeys and it would be perfect.