someone above said it best...when you get that feeling...intensify your scan.... whether you are flying glass or steam....... ADI ADI ADI.. get the scan going... mostly on the ADI....
I have had it happen just a couple times to me in flight... but I take it very seriously ESPECIALLY when I am doing a low vis takeoff.... or in heavy rain...etc.....
Other than mechanical failure... the VAST majority of GA accidents are because of VFR pilots ( or even low time IFR rated pilots ) pushing the wx beyond their ability. JFK jr is just such and incident... fairly new instrument pilot dark night... overwater... probably little or no horizon..... set up for vertigo.