I've spent 12 months working with cable and getting the best set up, it's not easy when you haven't got the tools VM have!
Yes it's lots of of trial and error to get your system working great.
I've had 6 different receivers
Used various different servers with all combinations C lines, N lines, oscam. I've used different splitters, powered amps new cable, new connections.
I now have a great working system which comprises of the following.
VM hub in modem mode
Dlink DIR 880L wireless router
Any receiver connected by Ethernet to router (all mine actually go to a network switch then the router)
Running mgcamd on two single receivers and oscam on my main receiver as it twin tuner plus satellite. 2 PCs and a laptop hammering (and I mean hammering by my kids) the internet and all receivers switched on - no issues.
So don't give up as you will get there in the end.....