I ask because I'm considering the same thing, but I find it surprising that you can't find anywhere that will take you without an undergrad in CS given that you have work experience, especially given that your degree is in IT, which is very related.
I think they've relaxed requirements a little but it's still not easy getting into comp. sci. from another field.
About work experience, the Brown advisor said that, for them, it's a mixed bag. A person from industry knows how to produce an application but there may be large gaps in knowledge. For example, a developer can go a long way using ArrayList in Java but not know a thing about it or alternatives, especially if code generators are involved.
A good example is University College London: http://www.cs.ucl.ac.uk/admissions/msc_computer_science/
The so-called generalist programs are for non-CS majors, while the specialist programs are for people with a CS or related background. Degrees in the natural sciences commonly involve introductory programming courses, so those may be a good fit.
Unfortunately, my wife would have a hard time finding work in her field and my daughter loves her school and friends too much. I'd feel awful asking them to make the sacrifice.