Upon reflection, it's funny how the clear divisions between strata of 'traditionalists' in East and West are exactly mirrored in their reactions to the Gregorian Calendar (for the Easterns) and the Novus Ordo Mass (for the Westerns). Take the following three strata, where 'X' indicates the Gregorian Calendar or the New Mass, and Y represents the Julian Calendar or the Tridentine Mass;
1) Those who believe the X is equally valid, if perhaps sometimes rather problematic. These people prefer Y over X for historical, cultural and various reasons, but do not see X as heretical.
2) Moderates. These believe X is seriously problematic and has heretical tendecies - Y is the solution to these modern heresies. These believe that while X is not invalid or graceless, they prefer to wall themseleves off, keeping Y and the true uncompromised faith, forming a sort of resistance, hoping for better times.
3) Extremists. These believe X is heretical and invalid and graceless. Those who adopt X have become heretics, outside the True Church, and that grace leaves that jurisdiction. Those who use X may only be saved if they renounce X and join Y, the only place where true believers may be found.
In the West, 1) is represented by the indult traddies, 2) by the SSPX and suchlike vagantes, 3) by the sedevacantists, feenyites, pius xiiiers, palmarians.
In the East, 1) is all those on the Old Calendar who maintain communion with Constantinople, 2) is ROCOR and the Cyprianites (Moderate Old Calendarists of Fili) and the Old Calendar jurisdictions of Romania and Bulgaria, 3) by the extreme True Orthodox Church of Greece and suchlike.
Now, isn't that curious? Comments and contributions welcome.