Ok, I got my 905 and here are some first impressions.
It's a V3 without the switch on the base, which means it can be stood up on-end. Nice.
Very solid feel, the threads are well machined and smooth. The ergonomics are spot on IMO.
With the supplied 901 atty it has a mellow vape with lots of vapour and lots of flavour but less throat hit than a 510. I quite like it.
The switch has a very solid click and needs a firm press to activate. Coupled with its location on the narrow part of the body I'm not worried about it getting accidentally activated in a pocket. On the other hand, I wouldn't want to leave the atty attached in a pocket for fear of it getting snagged and breaking off at the base.
The down side is that it did the zombie activation thing on me one time. Atty heating up, no light. This was just after I'd taken a puff and I went to put the 905 down and heard it sizzling. I didn't give it time to see if it would switch off by itself, but unscrewed the atty to cut the power. I screwed it back in again straight away and things were back to normal. Next time I'll try pressing the switch again to see if that will turn it off.
That's a pretty bad down-side

Not enough to make me give up on the unit, but I don't *trust* it and find myself listening for a sizzle after every puff and unscrewing the atty every time I put it down.