Track-It! is great for a small-to-medium sized enterprise that has a fairly small IT department but needs far more control of tickets than just email and spreadsheets. It scales well enough as IT departments grow, adding techs is simple enough, as is changing the workflow. A large company would probably be better off with a different solution. The lack of easy customization, and the shortcomings it has in workflow templates (which would be a nightmare for project management) means it won't scale up that far.
We have rarely needed to use Support for BMC Track-It!, but in the times that we did need to use it, they were excellent. The biggest issue is that after not paying for support for about three years, now that we NEED support, it is too expensive for us to receive. This is due to the way their support is billed. So long as you never drop support, then you should be fine.
BMC Track-It! is much more bare bones compared to ServiceNow products, and if your department has the money, ServiceNow is a much better option. Not only is the Knowledge Base much easier to create and publish articles, but the asset management in BMC Track-It! is practically useless. BMC Track-It! is more cost effective, and with a small amount of technicians there's likely no reason to need a bigger solution, but it leaves a lot wanting.
The biggest positive impact it had on ROI was that the software itself didn't require any expensive ongoing maintenance contracts since it was installed and managed by our organization.
The negative aspect of this is if there was a major problem with the software, then it would require contacting the vendor, at which point it could become expensive for a service call.