So, in corporate IT land most people seem to work the useful age IT assets is between 3-5 years.  When they get older than that they replace them. There seem to be many reasons for this and I do know organisations that completely ignore this and have to resort to TradeMe and eBay for spares when things break.

What about at home?  I tend to upgrade my laptop every three years or so just to keep up with latest and I push it quite hard (18 months into current one and already wishing I spend a wee bit more on it!).  But then there are things that performance is less of an issue. When would you replace a router or a switch if it supports all current standards?  What about a NAS?

I started asking myself this recently especially around my Synology NAS a DS1315+ which is now around 5 years old.  It still works and does what it is supposed to do, a bit more performance wouldn't be unwelcome.  However if it failed it would be a serious pain in the neck.  Would a new unit have less chance of failure, is it really worth replacing just to avoid that risk?