I would, of course, make certain that the priest knew I was Orthodox and generally speaking, I have had my home priest either phone, write a letter of introduction or e-mail the "other" priest in order that I might receive Holy Communion. There has never been an issue other than in the ROCOR church (back in the early 90's). Orthodoxy is Orthodoxy. We are one across jurisdictions and if this is not so, then frankly, I would not care to be in such a Church that is divided asunder like this. But thankfully, that is not the case. I've been communed in Carpatho-Russian churches, Greek churches, OCA churches, Serbian churches and Antiochian churches. Some of these churches have been Old Calendar and most New. My godfather is a Ukrainian Old Calendar priest, the church into which I was brought into Orthodoxy is New Calendar church. The Faith is the same. I'm confused as to why you would never receive the Lord's Body and Blood in another Orthodox church? We are one family. Oh... there are a few churches who are not in communion with the rest of the Orthodox Church but that is an entirely different case.
Anyway... I diverge. My experience has been a very mixed one with ROCOR... both high and low (currently quite high). As I mentioned previously, it was our great privilege to venerate the relics of St John of Shanghai and San Francisco in his reliquary in the church in San Francisco. It was a life-changing experience for us both. Glory to Jesus Christ.