I just ordered some from Lubrication Specialists for $6.65 a QT. Now that it's been out for a while, does it perform as well as advertised? Amsoil's website says you can go twice the factory drain interval. That would mean leaving it in my 05' 6R for 15,000 miles. Sorry but I just am not buying into that hype. 7500 miles maybe. Anyway, what do some of you think of this oil?...esp regarding shifting, smoothness, engine temps.