I've been mining XVG for 24hrs, started with Antmine when there's was only 33 miner and now its like 500 miners, and all throughout the 24hrs, I discovered Unimining and been jumping back and forth between the two for comparison. Never tried zpool.
So my observation, with Antmine you get bigger payment but you need to wait longer while Unimining you get payment like every 10-15mins.
I got 185mhs(ETH )and 7000mhs(XVG) on 6x rx570. And so far I got 84XVG in my wallet and I still have 13XVG in my Unimining account.
I prefer Unimining, I did not experience any problems with unimining, I've used the 5766 port and declared the c=XVG value. I'm not sure if that makes a difference.
Either way you can't go wrong, I just prefer seeing continuous payment compared to waiting for hours.