The ease in which it is used for any network automation needs makes this product very attractive indeed! It can be easily integrated with other products too making it even more useful than just an automated tool itself as well (such has OOBE).
I have not come across anything so far that would make me unhappy about using GluWare's solution - everything seems good enough from my perspective. They could definitely improve their customer support service though by having dedicated engineers available 24/7 all around Europe or maybe they are already doing so? We use Glue Ware mostly because we're solving some fairly unique networking requirements here - our customers love us since day one :D.