In reply to ralphio:
Hidden Chimney is probably the one to go for if conditions are good, although I did it last year when there was little snow about and found it quite difficult in places. I think the protection was generally pretty good though. Similarly, did Invernookie recently in thin conditions (powder and frozen turf) and it was definitely nearer IV than III. It would be a cracking route with good neve, although protection was quite hard to find in places. There are some superb routes in Sneachda of all grades so I'm sure you'll have a great time.