Ask HN: Ethernet Over Copper Vs. Cable?

We have been having serious issues with our offices cable connection stability. We have a team of about 18 guys and we use a good amount of internet every day. I was just talking with an alternate provider about getting Ethernet Over Copper and its appealing because of their 100% QOS guarantee. The thing that scares me a little is that its a 10Mb up/down connection based on our location. Our current cable connection is 70Mb down 5 up. Can anyone speak to the real life implications of this? Will we need to put bandwidth limits on each of our connections with a much smaller download limit to avoid having horrible congestion? In short, the stability and consistency is very appealing, the speed is a little scary. I can't seem to find any really good real life comparisons after Googling a bit. Any thoughts/help would be much appreciated!