The volume is going from Full to 0 in 1/3rd of the slider on my iPad 4. Newest iOS and app version. On my screen that's about 1/2 an inch and very jumpy. Ipad speaker and Bluetooth do make use of the entire slider.
I'd really like a much longer slider anyway. Always nice to have more accuracy available.
The volume slider issue was a gramofon issue and was known. Gramofon informed me it was supposedly fixed n the newest update.
The update has been rolled out, my Gramofon has been inaccessible for a couple of days. It took a factory reset and reconfiguration to get it to work again. I think gramofon support did something to it too, because after the reset it still did not work for a couple of hours. I mailed support and when I got a reply it suddenly magically worked again. Support was very fast, BTW.
Anyway, the slider now takes about two thirds of the length of the slider to get to 0. so it's improved a bit, but still is not quite as smooth as the unit's own speakers or Bluetooth. I hope they will work on it some more, then it will be perfect!