(posted at 10:33PM BST) 
I would like to go on record that one of the key reasons why I took Spilsby Internet Solutions on as a full-time venture was because I had worked in the industry long enough to see how *not* to do things and one of the places where I worked was Centrinet.
In comparison, Smartbunker appears to have been trading since 2003 and has many millions of capital behind it (I was privy to the original purchase price of their premises when I was still an employee) yet they only have single-provider connectivity, they do not specify the speed of said connectivity on their own website and they make the classic mistake of advertising 100% uptime.
A look at their network diagram shows dual Cisco PIX firewalls at their borders; a single remotely-exploitable flaw in the PIX's operating system would bring down a perfect 100% uptime - all Smartbunker can guarantee is that they have 100% uptime *so far*.
On the other hand, I am operating on an annual five-figure budget for hardware/datacentre/transit fees; I currently have a presence in three datacentres (Redbus Meridian Gate, London; The Planet, Texas; DediPower, Reading) and will soon have a presence in another yet-to-be-announced datacentre a bit nearer to my own base of operations.
My own border routers run on different CPU architectures, a mixture of operating systems and a variety of different routing daemons providing BGP/OSPF routing across the entirety of my network - a monogamy of any kind in your network infrastructure is a big no-no!
In all of these datacenters, I have multiple transit providers and dedicated links (UK to UK is via shared access to a dual SDH ring) between my disparate networks linking them into one - which means I have total datacenter redundancy.
I am not a multi-million pound venture but even with all that redundancy, I wouldn't bet the reputation of my business on a claim for 100% uptime because one day, I would get called out on it even it were for only a fifteen second outage.
Just for laughs, Google runs the largest collection of datacenters in the world as well as the world's most popular website but not even Google claims 100% uptime... and of all the people I would trust to be able to make that claim, it would be Google.
EDIT: I just had a thought - Centrinet are Checkpoint resellers and used to bleat about how absolutely brilliant Checkpoint firewall products are - so why aren't they using them for their own enterprise-level hosting network instead of Cisco PIX boxes ?
It would also appear that Centrinet are no longer a Checkpoint Gold partner and have been downgraded to Checkpoint Bronze... nevertheless, the fact that they don't use the very products that they push to their customers for use as an enterprise-level firewall should say it all. | 
