I notice a disturbing trend emerging in recent times, where many who regard themselves to be genuine Orthodox Christians are in danger of succumbing to the temptation of Old-calendarist Ecumenism. There are certain pseudo-shepherds (wolves in sheep's clothing) who are steering their unsuspecting followers toward this heresy.
There are very real and perfectly legitimate reasons why various "Old-calendarist" groups are not and should not be in communion with one another. Many of these groups are simply not Orthodox, no matter what they call themselves. Simply being anti-MP does not automatically make one Orthodox. Simply following the ancient calendar does not make one Orthodox either. The Papists made use of the old calendar for well over 500 years after their schism, before adopting a different one. This did not make them Orthodox one whit. To be Orthodox, one must accept the WHOLE faith, in its entirety, without alteration or innovation.
What is the largest of these supposed TOC groups in America? The HOCNA? They are not Orthodox; they have been preaching multiple heresies with bared-head for years, and show no signs of repentance. So no True Orthodox should unite commune, or concelebrate with them. And yet, there is another supposed Greek TOC group, with parishes sprinkled mostly in the eastern half of the U.S., which in official documents is now calling the HOCNA "true Orthodox Christians" and a "true Orthodox jurisdiction". They have also prayed and held services together with HOCNA clergy. Each passing day the vicar bishop who presides over this jurisdiction sounds more and more just like the heretical crew in Boston. Orthodox Christians with discernment should flee this group as well, until they modify their false views and clarify their hypocritical positions.
The Kyprianites, aka "Synod in Resistance," are crypto-ecumenists, and not Orthodox. That would extend to the Agafangelites as well, who of course, are in communion with them and consecrated bishops together with them.
There is at least one so-called "Matthewite" group, who do not hold to the traditional Orthodox confession historically held by the GOC synod of Greece, but have gone aside, teaching a number of strange doctrines, including rejection of various types of Orthodox holy icons. (e.g. the icon of the Holy Trinity, wherein the Father is depicted as "the Ancient of days"). They use heretical reasoning to defend their rejection of the holy icons, in similar fashion to those arguments used by the H.O.M.B. in Boston and the schism formed from their schism by Gregory of Colorado.
The ROAC seems to put forth a good confession of the Faith in official documents, but I have little confidence in the bishops they have chosen to administer the flock in North America, both past and present. I do not know if it is any better over in Europe. They have officially in Sobor rejected Cyprianism, which is necessary for all Orthodox Christians to likewise reject.
Information about the remnants of the faith communities which used to be unified under Met. Vitaly is hard for me to come by.
Information from the "RTOC" is rather limited as well. Vladimir Moss claims they have rejected Cyprianism in some sort of official capacity, but my requests for any kind of documentation demonstrating such, have gone unanswered.
All genuine Orthodox must reject the crypto-ecumenism of the Cyprianites, and ought to shun those groups who maintain communion with them, such as the Agafangelites.
All genuine Orthodox Christians must reject the heretical arguments made by the iconomachs, regardless of which group they reside in, who seek to lead astray the unsuspecting flock, with their vain and trifling attempts at justifying their rejection of icons of the Holy Trinity, wherein the Father is depicted as "the Ancient of days".
Of course, no one can subscribe to the diabolical evolution heresy and be a Christian either. If any clergy preaches evolution nonsense he should be rebuked and shunned as being a priest of Satan, and not of Christ.