In reply to davtay:
Macdui is fine in good weather (about 16km round trip and 800m of ascent from the ski car park), but has very tricky navigation in poor visibility. You can go up either via Fiachaill a' Coire Cas (straightforward) or Fiachaill Coire an t-Sneachda (a bit scrambly, Grade II if you keep to the crest, but difficulties all avoidable on the right), and return via the W side of Coire an Lochain. Best to avoid the Goat Track out of Coire an t-Sneachda, which can be avalanche prone or very icy.
> if its that bad we will turn round and come down, were not scared to admit defeat, there's always another day.
That's a very sensible attitude, but you need to be aware that once you are up on the main Cairngorm plateau, there are often no quick and easy routes down to lower level.
Post edited at 18:56