Hold on a minute. Before you're too quick to close this question, this isn't a "Tell me which software is best" or "What software do you use" question.
What I'm wondering is, is there any actual hard data out there for the percentages/numbers of UX experts using the various different pieces of usability testing software (Optimal Workshop, Silverback, Morae, etc)?
You know, the sort of thing that one sees for internet browser or OS usage. Perhaps even like the surveys that have been compiled by Stack Overflow on programming languages that software developers use each year, I imagine there might also be something similar done at UX conferences or websites about software choices for usability testing.
Perhaps a bit tricky to answer, I suppose a question that must be asked about it is "What defines a UX expert" since it isn't exactly a licensed profession, and it is probably more diversified and specialized than ever before.
Gathering the data is also a bit trickier since it isn't automatically logged on the internet as data on the use of such critical software as browser and OS is.
But many industries manage to judge market penetration levels just fine, so I'm hopeful that various software vendors might provide some data on their subscription or usage analytics.
If 'professional' is a bit hard to define, then percentages/numbers of users overall amongst the major alternatives would also be data I would be interested in seeing.