Yes, I use sliding scale. I'm a bit irritated that when I mentioned that in a question I raised a while back (not about sliding scale) the consensus seemed to be that I'm somewhat dim-witted for actually following my doctors instructions.
I adjust the amount of Humalog I take before meals based on my pre-meal blood glucose reading. I also carefully monitor the amount of carbohydrates in everything I eat or drink. I know which foods will kick my blood sugar through the roof and deal with it at the next meal-time blood glucose reading.
My A1C has been below 7.0 for the last three years using this approach. I have adjusted the base value for the sliding scale on my own a number of times but have always discussed it with my doctor and he's told me that I'm competent to manage it on my own. I adjusted it recently and think that the next A1C results should be significantly lower. I trust my doctor's judgement and he has an excellent reputation as a doctor (not an endocrinologist) who knows how to manage diabetes. I have not yet seen an endocrinologist... I thought about it but don't feel the need.
As far as I'm concerned, there's no point in paying doctors for an appointment if you're going to hide things from them. If you disagree with your doctor's approach to diabetes management, say something... have a meaningful conversation about it. Your doctor can't help you deal with your disease if it's not a cooperative endeavor.