1. Northwest, .925
2. Pacific, .925
3. Central, .923
4. Northeast, .919
5. Southeast, .917
6. Atlantic, .916
Quick and Lundqvist ended up with almost identical situational save percentage stats (both .933 at even strength, with Quick just slightly ahead on the penalty kill .908 to .905). The Kings faced a higher percentage of shots against on the PK, which caused Lundqvist to slightly edge out Quick in terms of overall save percentage by the narrow margin of .001. The closeness of those results, combined with Quick's extra workload and the Kings' late-season playoff charge, has made Quick a recent trendy Vezina pick, an impressive comeback given that it looked like Lundqvist had the award sewn up by the All-Star break.
Assuming both goalies were competing in the same environment, it would indeed be very difficult to separate them by the numbers. However, if each goalie's numbers are adjusted relative to their individual conferences, then Lundqvist opens up a decisive edge over Quick:
Conference-adjusted situational save percentages:
Quick: .930 EV, .907 PK, .941 PP
Lundqvist: .936 EV, .906 PK, .974 PP
Multiplying those out by the league-wide average frequency of shots against in each situation, Lundqvist ends up with a conference and situationally adjusted save percentage of .932 compared to .927 for Quick.
Another option would be to adjust each goalie's numbers relative to their division, although in that case the much smaller samples means it would be important to remove each goalie's results from the overall numbers (i.e. the Pacific without Quick and the Atlantic minus Lundqvist). That calculation only increases the margin in favour of Lundqvist, given that his .933 looks much more impressive when stacked up against the combined .912 put up by the rest of the Atlantic division, with the other netminders in the Pacific still combining for an above-average .924 mark even without the contributions of that division's Vezina candidate. Using the divisional numbers and the same correction for shots against by situation, Lundqvist's adjusted number moves well ahead of Quick .935 to .927.
To me, anything close to a tie suggests Lundqvist should win because his elite track record means that it is much less likely that his terrific season was based on luck or other secondary factors. I would pick Lundqvist even assuming that both goalies faced identical shots against for this reason alone. Adjusting for the east/west disparity only makes the choice that much more obvious, in my opinion.
Relying on historical records to evaluate a single season of goaltending is somewhat unfair to the goalie who is four years younger, but it is simply the reality of dealing with uncertainty in goalie evaluation (and why I don't think single-season awards are all that significant). This was Lundqvist's third season in a row at .920 or better while Quick's previous career best was .918. Future years may well prove that Quick's true talent is in the mid- to upper-.920s, but as of right now that's probably not the smart way to bet.
Another relevant piece of statistical info is that Quick's numbers were much better at home (.936 at home compared to .922 on the road), whereas Lundqvist's numbers were higher away from home (.934) than at MSG (.926). That doesn't necessarily mean much, variance is naturally going to be higher over 900 shot samples than over full-season results, but since road numbers are counted by a variety of different scorers they are less likely to be subject to bias. It is also worth noting because both goalies have been pretty consistent on the road over the last three seasons, with Lundqvist maintaining a steady .011-.013 gap over Quick:
Quick: .915, .916, .922
Lundqvist: .926, .929, .934
This year Quick's home numbers shot up while Lundqvist's improved slightly. Again that could be reflective of improved play for both goalies, but it could also be partially related to shot counting or team factors. The other interesting thing to note is that this is the third straight year that Lundqvist's save numbers have been better on the road. MSG is known for poor stat recording in general and it is possible that his numbers are being at least partially suppressed at home, especially given that Lundqvist faced an average of 5.6 more shots against per 60 minutes on the road compared to at home in 2011-12, coming on the heels of a 6.0 difference in 2010-11.
On the other hand, Quick's shots against rates were 26.5 at home compared to 28.0 on the road in 2011-12. His shots against rate at home has actually increased in each of the last three seasons, at the same time as his road shots against rate has been continually decreasing. That's not the typical statistical profile of a goalie being disadvantaged by his home scorekeeper. Overall, the home/road numbers are just one more reason to be a bit more confident in the Swede than in the American.
Taking their histories into account along with the conference disparity, I think Henrik Lundqvist deserves to win his first best goalie award. It could be argued that the shot quality allowed by the Rangers was not typical of the rest of the Atlantic Division, or that goaltending in the Western Conference in general or the Pacific Division specifically was simply a whole lot better than it was out East, either of which would mean that the adjustments above are unfair to Quick. I would certainly listen to anybody willing to make those arguments, but right now I don't see enough supporting evidence on the table. Shot quality arguments are always particularly murky because of the lack of good data, and subjective comparisons are very difficult, particularly for two teams in opposing conferences.
As an aside, this season has made me wonder at times whether we can continue to rely on the general assumption that EV shot quality is relatively constant between teams. The two major pieces of evidence in that direction are probably St. Louis' 2011-12 goalie stats and the conference splits displayed above. In the aggregate I think 5 on 5 shot quality is still probably not all that important for most of the league, but if there are some significant effects on the margins that would be important to know for goalie evaluation.