Hi Snoodleberry, great news that your scan went well!
I can't advise as to the merits of sliding scale in labour as this is my first baby. Other posters have though so I'm sure they can give opinions specific to labour.
As to my experience of sliding scale in general though... The reason they wanted a sliding scale, and that I agreed, was that I had to be nil by mouth in case of needing to be anaethestised for emergency surgery. I hadn't eaten since lunch and it was 9pm, so I was worried about the baby not having nutrients and getting dehydrated. So they gave the saline drip, which contained glucose, and then also an insulin drip to offset it. The default setting for the insulin drip was 4 units per hour. That adds up to way more insulin than I would normally be having (not sure what the rate of delivery for glucose was). I told them that it would send me hypo, and sure enough it did. Then their correction of glucose made me high (and so it went on all night).
I think, in theory, if it were managed expertly, a sliding scale could lead to good control. BUT, as far as I can see, the people managing it aren't as experienced as we are at managing blood sugar, nor are they familiar with the individual patterns and nuances of our particular bodies.
Delivery for me is, I HOPE, a long way off, so we haven't discussed sliding scales etc. However in light of this experience I plan to be firm in refusing one. I remember Ripley saying that she kept an hourly log of blood sugars during labour and was able to use that to prove that she was managing it herself and didn't need sliding scale.
In addition to all that, I expect the experience of labour will not be improved by being hooked up to a drip, which is utterly loathsome and to be avoided at all costs in my view!