Excellent post Quest.
I have become good friends with a fringe group of Seventh Day Adventists in Barbados who call themselves, "Truth for the Final Generation". They are a great group of guys and I have learned many things from them and they think highly of me as well despite me being a Pentecostal "Sunday Keeper" (as they teasingly like to call me). As a matter of fact they believe that more "Sunday Keepers" will enter the kingdom ahead of many of their fellow SDAs who exhibit no traits of love and are caught up more in rules than in Jesus.
That being said I have also had some lively discussions with them about Sabbath and Annihilationism (I am supposed to be writing a paper for them on why I believe that hell/lake of fire is
literally eternal). I don't recall ever believing that Sunday is the Sabbath and I remain convinced that Saturday is the official "legal" Sabbath day of rest. No change.
What I am NOT convinced about is that I MUST hold church services on Saturday. I think it is great that some do. Heck, it is great if you can have a church service any day of the week. Worshipping God corporately or individually is not limited to a particular day. Sabbath is a rest day. And since I practically work six days a week anyway I do try to rest on Saturday.
But the truth be told, the Sabbath is indeed Saturday and if we are going to be Biblical then we must stay with that truth. However, it is NOT something we must be legalistic about. Saying that we MUST conduct church services on Saturday would be legalistic.
One other thing, my SDA friends in Barbados agrees with Quest's last point about Christ being our Sabbath which is why they do not see any issue with fellowshipping and receiving ministry from "Sunday Keepers" such as myself.