I assume by jamieson set you are refering to a caputred hollower, which has advantages, the main one being it is more pf a precision tool, especially when mounted with a laser setup and its versatility. I have 2 different homade hollowing rigs one being a standard jamieson style d-handle the other being a kelton style rig, Another big plus on the captured rig is the ability to use tools from various manufacturers. My personal choice of tools in the system is from monster lathe tools. The final benefit is it puts less stress on the the body of the turner. The cons of the system are the time it takes to setup for casual turning, the cost if you aren't making it yourself.
The termite is simply a ring tool which is great for endgrain, though I prefer a berger hollowing tool as it cheaper and I can use it with with less catches. It does its job well but like all turning tools it takes being sharp and lots of practice to get the most benefits out of it, but once you learn it you can certainly hog eng grain fast. The big cons include a steeper learning curve than some other tools, big catches are hell on your hand, wrists, elbows and arm in general, it can clog fairlly quickly lending to those big catches at unexpected times and lastly there are better tools for hollowing grain running in other directions and especially for burl work.
The one thing I will say is you can make bgoth tools with improvements and for less money if you have some rudimentry metal working tools and are willing to go through the effort. I have both strain and swan necked termite bits for my captured rig as well as a long heavy duty handled model.