Generally, it is advisable to continue on a valid visa. If on EAD and 485 or EAD renewal gets rejected for some reason, then it is an out of status and have to stop working.
It happened to my colleague's friend who was 'flagged' just because he unknowingly traveled on 9/11 morning from Newark, non-american, etc. FBI agents visited question him couple of times and he thought everything would be fine. But, now his EAD renewal was getting rejected and even court isn't helping it seems. He lost his job and fighting via legal channels. He doesn't have anything negative and his wife is an american, so he may get it cleared someday, but still have to go through it. This is just an example, but a rare case and shouldn't really be a concern for everyone.
Many people use EAD and change jobs since the risk factor is very low when everything is properly documented.