You need to knock 100 quid off all AMD GPUS for them to make sense right now.
430 for the FuryX make it a good alternative to the 980Ti
350 For the Fury makes it stack up nicely against the 980 and be considerably cheaper than the 980Ti.
300 for the 390X makes it a bit cheaper than a 980 for a slightly slower card that draws much more power.
At those prices the AMD options look to be on par and offer a choice. They aren't obvious winners but in line. Knock another 30 off and they become more attractive than nvidia's offerings, and another 20 again (so in total a 150 quid drop) and they would sell extremely well: FuryX for 400 vs 980Ti for 500, Fury for 300 vs 980 for 360, etc.