I have several customers using T-Hub. Not sure that I like the software at all though, it is desktop based. I would like it to be in the cloud.
I do have another solution, but it requires some work to integrate. Called Teapplix.
http://www.teapplix.com/pricing.html
Even if you max out their biggest plan (which a lot of my customers would) it is still less than Unify.
Get in touch with me if you would like help integrating with them.