I use 3Essentials for a few of my sites. They have good up time and their mail system is nice. Installing DNN yourself can be problematic with them because you actually have to submit a ticket to get them to change permissions. However, they will install DNN for you if you ask at no charge.
The speed of their network is around average. I have had a few issues with their data services. Some modules time out because of slow data access. However, these problems are usually short lived.
Their support is superior to most hosts. They are on live chat very frequently and the wait is usually less than 5 minutes. I have been up at 3 AM and they have been available to assist me live. They are also friendly which is something you don't see with most hosts. Their ticket system is pretty standard. I normally get a response to any question within 2 hours which is actually quite good.
Their system uses Plesk which is a great management system. I personally prefer H-Sphere but Plesk is still quite nice. The system is fast and easy to use.
My one complaint is the structure of their plans. They sell a 10 pak and a 50 pack of domains. However, they only allow 1 alias per domain. So if you have a .com, .net, and . org pointing to the same site, you will have to pay for it. That really becomes problematic for a reseller. I asked if I could get a custom plan allowing me to have unlimited domains and aliases. They respectfully declined my request.
So, that is the long answer. The short answer is that you will not go wrong with 3Essentials especially if you have only a few domains to work with.
Hope this helps.