St Benedict of Nurisa in Wichita Falls, TX has been known to sing Old Roman Chant on occasion, on a great feast here or there. (Pentecost, Pascha, etc..) As Old Roman is typically not especially noticeably different from Gregorian by the average person, the average person in the pew is not aware of this. Yes, the melnicki edition with german introduction, circa 1969 is the one that is used as that is the only book existing which has Old Roman Chant in 12th century style neumes which is the legible standard for most gregorian chant sung today. One of the friends of their cantors shared this fact with me many monthes ago. This St. Benedict of Nursia church has one of the strongest sacred music programs of the Antiochian WRV. They also have a very nice rood screen and sacred art inside. One can quible with a few details but all and all quite good. http://www.antiochian.org/parish/34916
"The English Gradual Set to the Texts of the Orthodox Missal" is the standard "simple psalm tone" gradual for propers used at the majority of Western rite Orthodox Churches in both ROCOR and Antiochs Vicariate. It's rather utilitarian and lacks the beauty but the job is accomplished of having propers sung. http://www.stgregoryoc.org/wp-content/uploads/2013/10/Trinity-Pentecost_season.pdfhttp://www.stgregoryoc.org/music/
"The Plainchant Gradual" is the standard that is used in the handful of Churches that sing the original gregorian melodies, as it was for a number of Anglican protestant churches. Having been priviledged to hear them sung from this week after week, I can testify that it is almost equal to the latin in beauty. (It is also currently the unofficial standard for a few Anglican use Personal Ordinariate Roman Catholic Churches. In their case it is rarer because their use of the novus ordo lectionary does not align with the tridentine and pre-tridentine propers, but some ignore the misalignment and do it anyway.)http://media.musicasacra.com/books/plainchant_gradual_1-2.pdfhttp://media.musicasacra.com/books/plainchant_gradual_3-4.pdf
Eventually a Gradual inbetween the two extremes (utilitarian/simple vs. beautiful/very ornate) may prevail. But thats a work for someone go undertake in the future. It can be done and ideas for an intermediate gradual have been proposed. Such as sing the same ornate Alleluia and communioon antiphon melody over and over again but with different words, instead of the same simple melody with differant words or different words and diff. melody every week.
In the two Antiochian WRV Churches in Massachusetts they have been known to sing latin propers and ordinary on major feasts.
In two or three of the Antiochian WRV Churches in Colorado they have been known to sing latin propers and ordinary on major feasts.
I believe the Detroit area Antiochian WRV also hires a cantor and has used latin before. Surely there is probably a few others that have used latin for the music on major feasts, but for the most part it is a minority that does this. The majority used only english, or 99% english at all times.
In many cases the ability to sing the propers to their original melodies requires the paying of skilled singers from university music programs. Unlike in most traditional roman catholic latin masses where the majority of the scholas are based on non paid volunteers who although amateur at first, improve with time, this is typically not the case within the anglican, anglican catholic tradition with whichparishes who do this typically take more influence from. So, ultimately the case of improving musical standards requires a motivated pastor and greater numbers of lay people, who often times would rather pay someone than try to learn it themselves.