In the past I have used Castrol magnatec 5w30 in my Lexus and it was fine but at this oil change the garage I used put in Millers trident 5w30 and I must say it has been good so far, although it is early days. They also flushed the engine with Wynns before putting in the oil, however I am not exactly sure what the procedure is for this.
I was a little wary of putting in something other than castrol however when I booked it I asked for the part number of the oil and read up about it and seems to be quite highly regarded and is more or less the same price as magnatec, therefore I will continue to monitor it to see how good it is.