Hi, I have worked with the Volant CRTi for many years. The tool is very reliable and very easy to Rig-up. Key is to ensure the Driller is comfortable in operating the Tool.
As it's a purely mechanical tool with Torque Activated Wedge Grip technology, you do not have to worry about hydraulics etc. The operating procedures for latching and un-latching are very easy. Running speeds will depend on how comfortable the Driller becomes running the tool.
The overall operating envelope of this tool is quite big. I have both drilled / reamed many strings to bottom.
I would recommend this tool for problematic hole condition as well as from an HSE perspective.