Basic setup is ok, synth benchmarks shows nice performance
In coffee-lake, as i can see from specs, main difference is added edram L4 cache, which is used as gpu vram (i currently use this embedded gpu, but looks like there will be no benefit from adding external video board because cpu seems to be unable to use this L4 cache for anything else then gpu, or am i wrong?), other changes are (compared to 5820k):
L1 both have 32kb per core, both are 4-way accessed
L2 both have 256kb per core, but 8700k have only 4-way access while 5820 can use 8-way - not sure if it is important for scrypt
Less L3 cache (12 vs 15Mb) and less access ways (16 vs 20) but cache frequency is faster (at least 4.2GHz without overclock, while 5820 operates at about 3Ghz)