I have the free version, and I haven't been able to connect to a machine yet. The first problem was that I didn't give ActiveX enough time to install the plugins in my browser (going through a VM). Once it finally installed, I am still unable to connect to 2 different machines. Mostly due to connection timeouts. I've been able to connect to both machines via VNC going over the same network connections, so I'm not thrilled with Kaseya's remote desktop product.
On the other hand, their audit information is top notch! I'm thrilled to get a maximum RAM number for a workstation, and a remote registry as well.
I'm going to be trying Level Platform in the next few days to see if they will do what I need (basically, provide a dashboard and remote access to a customers computer via a web browser/installed software on my Mac. We'll see.
I've also heard good things about GFI, but they're not cheap (I don't think so anyways, considering they don't post their prices).
Edit: Now I have to eat my words. I'm able to remotely access customers desktops now. I wonder what the deal was. I'm still trying Level Platform today, to see what they can do for me, especially for the cost.