In reply to AlH:
We were on Grey Corries last Monday and it was fine without either - one or two patches of snow on the ridge but easily walked on or passed. The Ben still looked to have a lot of snow as do the Aonachs so it may be advisable just in case - any snow we did come across on other hills was soft & sugary though some pretty large patches on summit areas - eg Geal Charn (Ben Alder) which was best to have sunglasses to cross due to the glare of the sun