I unfortunately bought a few laptops for a company with these cards. Dropouts weren't "sporadic" per se, but very frequent. Probability of dropouts seemed to strongly correlate with the amount of activity on the network, and happened several times a day. Once a card had "crashed", it was difficult to get it started again with less than a deactivate/reactivate cycle in the device manager.
So how did I solve the problem? Just like I did with my NUC (had a 2230 with similar problems there): Pop up the chassis and replace the cards with noname $5 150mb+BT Atheros AR5B195 card from Ebay China. Zero problems ever since, high speeds and 100% stability.
Not reputable, Intel. These cards should just be pulled out of the market until an extensive investigation has been conducted and the problems generally rectified.