Why would one choose one of the commercial/enterprise versions of Linux produced by the major distro companies? I am talking here about talking here about an Enterprise version (such as RH Enterprise Linux ES or SuSE Enterprise 8) rather than a personal or professional version (such as Fedora Core 2 or SuSE Professional)?

The websites tell me that the commercial releases are more stable and secure than the personal/professional versions? How true is this? My experience with SuSE Professional is that I would have to light the server on fire and throw it out the window before it would cause any instability. The only time I have had a problem was when a telephone repairman decided to pull the plug on the server. He couldn’t say why he did it just that he did!

So, besides the “support” is there really any difference between the commercial releases and the more main stream consumer releases? I am inclined to go with the commercial release for a installation I am working on but wouldn’t mind hearing some views. Any thoughts?

I saw a SuSE enterprise in action a couple of years ago, there were not many differences at user level, but it had a lot of administration and monitoring tools. I saw a workstation being completely setup from blank disk to full integration in net environment in 10 min. I think if you have a large, structured or heterogeneous (ie winnt+mac+linux+sun etc) net, or if the topology often changes (many laptops), it's worth the money.
Instead if you have only a few x86 machines on a ethernet network, with a linux-only environment, or samba shares are enought for you, and if the core system won't change, than any 'stable' linux distro will make the job. Please consider devolving a fraction of the savings to a development project of your interest.

Some of the enterprise versions have tweaks in them for specific commercial vendors - for example SLES (Suse Linux Enterprise Server) has some performance tweaks for Lotus Domino, something I spent a lot of time working on.

Novell's NNLS is very interesting commercial stuff, so is Ximian Desktop (Ximian has a couple different versions). Given those, and Ximian's Red Carpet - wouldn't it make sense to build an enterprise environment out of these tools, using a make of GPL and commercial vendors' tools?