Replying to Forward Lean Help

Does the forward lean on full tilts decrease your balance while sliding rails and such? I have had full tilts for the last 2 seasons and just recently found out that boots that have a more upright stance will give you better balance. I asked my boot fitter about this and he said that boots such as the Nordica Ace and the Dalbello rampage will greatly increase balance, which is what they carry for freestyle boots. So is it true that a more upright boot will help out with sliding rails and landings etc?