well for the purposes of gaming, gaming should be possible. As clear as that. but i do hear what your saying. the intel cpu typically adds £160 - £170 , So thats £1000 V £1170 but lets call it £1200 .. sure £200 is a lot but so is £1,000. You may aswell use the CPU and the GPU properly and save up that bit more (as an aside the msi chassis is bulky and plastic, wait for the refresh)
again, if somehow it was possible to crossfire or offload dynamically with the APU + 7970m then for £1k the performance would be beyond that of a 680m and more like a desktop 680 but they dont so the potential is wasted.
i think the best APU's will come towards the end of this year with the new A10-6xxx + crossfired with an 8870 (i think) gpu on a solid mid range £700 laptop
and just to emphasize my point:
https://www.youtube.com/watch?v=YJecUDvJrfc
30fps APU , 80FPS intel cpu