Because I had begun getting used to touch screen devices in general, my immersion was immediate.
I too dislike the left-hand holding situation a little, but I tend to hold towards the bottom instead and then there's very little difference for me. I do personally like page turn buttons and I thought a home screen button made some sense, but in all honesty I've rarely thought about it since I started using the device.
The K3 was my favourite technological device and it brought me countless hours of reading happiness, but now with the PW I find that I'm under a similar spell.
Oh - and another thing. Love that screen.