Steve OC is correct to point out that we are not quite comparing like with like. If you want to have full de-icing and aircon the difference between the two types narrows somewhat. However if you look at what you actually need for the N North Sea:
Aircon is nice-to-have but by no means essential or even asked for by the oil companies in their tenders.
The 225 functions quite adequately with the limited icing clearance as have the 332L / L2 for many years. OK perhaps there are a couple of days a year when you can't fly due to icing, but is it worth carrying the extra weight all year just for those 2 days? Again, the oil companies don't think so otherwise they would specify it in their contracts. However the 92 does not offer a limited icing clearance. No icing clearance at all puts you at a disadvantage on the N N Sea (unless you are Norwegian) as you are stuck with grovelling around at low level with the associated poor RT, traffic congestion and high fuel consumption. To be fair to Sky, since all blades are de-iced the extra to implement full de-icing (wiring, bigger generators?) is not heavy (around 190 lbs I think) you might as well have it (have to have it?) on the 92.
So what I am saying is that if you must have de-icing, this puts the 92 in a better light, whereas if you want to continue with standard N N Sea practice and use a limited icing clearance when available, the 225 has the advantage.
Regarding the fuel burn, its very difficult to be definitive about this - I spent several hours looking at the 92 and 225 flight manuals yesterday. There are too many variables such as: The speed / fuel burn changes massively with weight, as these aircraft have such a big range of possible weights (because they have such large disposable loads). The FM I have has no data above 26150lbs for the 92. Do you compare the 2 aircraft with the same load, or both starting at gross weight or what? What speed do you want to cruise at - the 225 favours higher speeds than the 92 but at lower speeds you can possibly get marginally better range on the 92.
I think the two are pretty close. I think the 225 is marginally better, and "more better" at higher speeds, but this would not be a deciding factor for me. For me it would be the autopilot, the screen design, the ability to descend at 165 kts at a vibration level much better than an L at 130 kts, and the ability to carry full fuel and 19 pax with bags every time - I have now modified my flight planning procedures. On arrival at flight planning, assuming the flight is more than 140 miles or so I just phone the line office and order full fuel. No need to wait for the load from traffic
Steve - you will be in a position to get a handle on operating the 225 in the near future, and perhaps you will also be in a position, or already have, a handle on operating the S92? What has been lacking in these threads is much "evidence" from people who have flown both aircraft -in fact I think its only me ( I mean that has posted, not that has flown both). So I hope to hear more from you in the future!
HC