Both AMD and nVIDIA's solutions suffer from microstutter and the problems are exasperated especially in surround gaming mode / eyefinity. I do not recommend either solution and instead suggest going with the fastest single card you can afford and overclocking it. Just make sure you get one with enough VRAM.
Until AFR is replaced with something more elegant this will continue to be a problem.
Until AFR is replaced with something more elegant this will continue to be a problem.