Could you tell us which amd driver, config, algo, and hashrate you have?
I'm very curious because last time I tested JCE-miner, it was very unstable! So I'm still running SRBminer with 4 vega 56, and it's very stable so far!
Adrenalin driver 18.6.1 or similar depending on the rig
Windows 10 1803
Rig 7x Vega 56 1408/800 1100/80, multihash 1968 on JCE miner
Hashrate 14400H/s effective
Consumption 1250W from the wall
Rig 6x Vega 64
same config
Hashrate 12700 effective at 1130W
All rigs using octominer riserless motherboards and server power supplies
Experienced no hashrate drop or any other issue associated with other miners
Discovered JCE since first GPU version and fell in love

yes I also feel the same way, CN-V7 JCE faster about 50-60 h/s per card and no hash rate drop like other miner for RX Vega card, but for RX 580 I think about the same with other miner.
CN-Heavy / Haven / Saber RX 580 faster about 20-30 h/s per card, but RX Vega I think about the same with other miner.
I hope JCE Dev keep updating and more active in this forum, because it's true in term of speed JCE is faster but in term of feature I think other miner got more feature that maybe for some miner it's very useful.
Keep the good work.