SO much to reply to....
OK, as far as I know, I'm the only 3.5 on SAU atm. I have a PNM35, which means VQ35 AND AWD. A PM35 is the RWD version.
Yes, I did get my car from Northshore, and like many people, I would buy again from them. (like Ian I don't work for them, just a satisfied customer)
The 3.5 is much more city friendly- instant torque gets it off the line better, but the turbo is (ultimately) faster once it manages to spool up....
Although I haven't tried it out, my thoughts is that the performance gap (stock/stock) is not that much. Plus you get that awesome 3.5 warble sound! One of my friends said he thought it was a V8!!!
The 3.5 has a (much nicer ) interior, really just my opinion ( it is upgraded form the 1st series)
You can only get an auto, which isn't a problem, cause of the Mrs i guess.
As said previously, only the 350RX models meet SEVS.
The AXIS models are a mixed bag- they have a variety of gear on them, some with more options, some with less, they seem like a far more personalised car.
If your in Syd, or close by, get down to Northshore and check some out. My money would be on a PNM35. My Mrs is happy driving ours...