In general you should stick to the non beta builds unless you have a specific problem with the current non beta build.  You can think of the beta builds as beta hotfixes if you like.  These eventually turn into releases but they are released as beta so we can get additional feedback from any customers who are comfortable running betas.

Usually if a beta has been up for a month or so it is unlikely to have serious issues at which point someone who is less keen on using betas should feel more comfortable about using it.

I do think we need more fine grained control in the upcoming SDC replacement so a user can indicate what kind of pre releases they are happy to use.  There will be some users who want to use alpha builds of things, but others may prefer to wait until something hits RC status before using it and some will want to avoid betas at all costs.

Usually a beta of a new major release would have more chance of problems than a minor release beta.

In the case of this beta of Virtual Desktops, it looks like the beta should have been changed to non beta some time ago.  So it is probably an oversight (Virtual Desktops is not my area so I am not 100% sure)

If we were to mail every user about each beta update then we would have a lot of irritated users who would think we are spamming them!  Opening SDC would inform you of any updates or you could install and run Component Tray which tells you without having to open SDC - so kind of like Windows Update.

Finally I must point out that just because you have a problem on one machine does not automatically mean all machines have the same problem.  So it may well be your issue is still being triggered by something else.  The bug could be in Virtual Desktops, or in the other app, or be the result of some strange interaction between the two.  If app A works on a machine and app B works on a machine but A + B on a machine results in problems, which is at fault?