YES!
One HUGE plus to note about VoIPServer is that Digital Hybrid are one of the only VoIP providers in Australia to run our systems in what's called a High-Availability (HA) Array.
In other words, we never use standalone servers.
Every one one of our servers runs in tandem pairs, connected by a system called Hearbeat (drbd).
Our systems lierally monitor each other, just like an ECG machine does with a patient in a hospital. If the "heartbeat" of the primary server node stops for any reason, the secondary node initiates a "failover", making itself the primary server node, and within 30 seconds our systems are live and fully operational again.
And while your VoIP service is now live on the new primary server node, we can perform maintenance on the server that's just experienced the failure ... and all that with almost no downtime whatsoever.
Occassionally VoIPServer will perform off-peak maintenance and/or software upgrades to our servers. These will always be done in the early hours of the morning to minimise any downtime to your service. During these times, your service will most likely be offline for a very short time during the maintenance window. However, you'll generally be notified at least 24 hours before any maintenance to our systems occurs, unless it is emergency maintenance, which is extremely rare.