I received my first paymout yesterday, I am a hobbyist miner with low hashrate. Because of technical issues with zcash z-addresses, I had to send my wallet file and my z- and t-addresses to extremal and received my first payment around 6 hrs. later.
Some things, like high payout limits, missing stratum support etc. may be disputable, and maybe other pools are better. But extremal is definitely not a scammer.