Grace simply means the Energy of God, i.e. God working in the world (as opposed to His Essence, or God-in-Himself), and is generally associated with the Third Person of the Trinity, the Holy Spirit, since it is God the Holy Spirit who acts invisibly in the world to bring men to salvation. There is a basic distinction, however, between charismatic and sacramental or mysteriological Grace. Charismatic Grace is the Holy Spirit acting throughout the world to bring men to repentance and knowledge of the truth. It is not confined to actions within the Church Herself. Sacramental Grace, on the other hand, is the action of the Holy Spirit within the Church, in particular in the Holy Mysteries, which actually carry out the salvation of men through cleansing from sin and unification with the Divine Nature.
This Grace is generally understood to be confined only to the True Church, i.e. the True Orthodox Church, and is what people mean when they talk about Mysteries being grace-filled or not, or there being no Grace in this or that jurisdiction. It means that, outside the Church, there is no true baptism or chrismation or communion, so that extra-ecclesial baptism is simply sprinkling or immersion in ordinary water, chrismation is simply anointing with ordinary oil and fragrances, and communion is simply consumption of ordinary bread and wine.
The complications arise when we discuss under what precise conditions a group of heretics can be expelled from the Church, or alternatively what kind of lapse of time may intervene between expulsion from the Church and loss of Grace. What I was told about the ecclesiology of the GOC (before the union with the SiR, mind you) was that the GOC had made a local decision that the new calendarists and ecumenists were outside the Church and devoid of sacramental Grace, but that as this was a local decision, it was not a matter of faith for everyone in the GOC to believe that the ecumenists were without Grace, but only that they must not have communion with them. So I knew individuals who believed that the new calendarists had no Grace and others who believed that they did.
This doesn't sit well with some True Orthodox, who believe that the question of Grace is itself a matter of dogma and that it is a heresy to believe there is or even might be sacramental Grace outside the boundaries of the Church, as defined by either an ecumenical or a local council. It appears that the union with the SiR was carried out on the assumption that the question of Grace is still unsettled; the only position on which the SiR was required to change was their assertion that the ecumenists were definitely still in the Church and definitely still had Grace.
So that is my understanding of the issue. I'd like to remind everyone to keep their posts irenical in this public forum, although any corrections of fact are welcome. We have a thread in the private forum that allows polemical discussion of the GOC-SiR union and the question of grace.