The hosting you'll get with this company is going to be very stable.  The fact that they can filter out bad traffic will help in this area, and they also use very nice servers to minimize the risk of downtime related to hardware problems.   They don't have an uptime guarantee that I could find, but from what I have seen with actual users, they do have a very stable service.

The biggest focus is on their DDoS features.  The DDoS features will analyze all traffic and ensure that only legit traffic is getting through.  This will help to minimize any impact from infected computers and other things like that.  From what I can tell, they do a very good job at this and can protect your site from most types of attacks. They break their hosting packges up into different types including remote website protection, Game Server protection, net services protection, hosting protection and more.  This makes it quite easy since you can go through and find exactly what you will be using the hosting for, and choose that.  Within each category they have four options to choose from based on how busy your site or service is going to be. Beyond the DDoS protection, they have good hardware, fair usage restrictions and several other features that make their hosting quite good.

The tech support with this company is easy to get in touch with and can help you to resolve most common issues.  They are good at detecting DDoS attacks, of course, and will begin preventing traffic almost immediately.

The hosting with this company is going to be quite expensive.  You're paying mostly for the advanced DDoS protection, which is a high end service.  For example, for general hosting it starts at $150 per month and goes up to $400.  Other options are less expensive, and some are more expensive, but they are all significantly more than you would pay with another company that doesn't give the DDoS services.