Here is the text from the Eastern Catholic litia:
Hm, Polish Roman Catholics also all the time are repeating "It is fitting...". A unique argument for this "dogma".
In my parish on Saturday during All-Night Vigil the troparion and canon of the feast were chanted, but on the next day (during Liturgy) nothing. And gold vestments, not blue.
Last days I had a kind of quarrel with my one of the best friends, who is very pious Roman Catholic, and I was shocked when she said that Orthodoxy didn't appreciate St. Mary's holiness.

She hasn't noticed that all the time we mention Holy Theotokos in prayers, say "Most Holy Theotokos save us" and so on. But what's I'm getting to, we have more important Theotokos feasts, including Her Entrance into the Temple, which Roman Catholic treats only as feast of remembrance (don't know if it's appropriate word in English) class. Moreover, we start and finish the liturgical year with Her feasts.
And as for the feast of Conception of the Theotokos, we focus on the fact that She was born of infertile parents, a many important and holy personalities of the Old Testament.