I always send buyer who pay via eCheque a message ASAP after notification that lets them know I know they've initiated payment, that I'll post as soon as PayPal clear the payment and what they have estimated the clearance date range to be, and that they'll receive further email updates on the status of their order as it progresses (but that I'll be happy to answer any questions in the meantime) - hang leaving  eBay / PayPal to create impressions re: postage time etc, for me.