We've been very happy with Nexcess. We use Magento, which is a pretty beefy system, so, it runs slow on most hosts. But, Nexcess has helped us to make it pretty quick. We actually tried another host that said they were the fastest host for Magento. We quickly came back to Nexcess when we discovered our site was running more two times faster on Nexcess. In addition, their customer service is great. They respond quickly to emails and are very knowledgeable.