This interests me greatly too. Although the volume is fine
on my E51, heavier use made me see the benefits of a QWERTY
keypad. So in the interim I had gotten a used E61i on eBay,
complete with updated firmware. Should have read about
volume issues first - it is a BIG problem! Between the
actual volume, the shape of the phone, and the narrow
"sweet spot" it's a real chore to use this in noisy
environments. Each time I have to fiddle with it endlessly,
press it tight against my ear, and hope that it doesn't
move. The E51 I just place next to me ear and use, with no
such issues. I'm desparately hoping that the E71 has
adequate volume and sweet spot too.