Other than the demonstration I saw at the Cleaning Show and The Natural Stone show I dont have any hands on experience of the Cheetah pad system (yet) What I have seen is impressive and I am considering using them as part of our arsenal.
I am currently trialling 2 other 4 pad systems at the moment and then will move on to the Cheetahs when the additional sizes are available and see how they compare.
My advice to you would be to complete a more general stone cleaning & sealing course first before looking at getting into marble polishing.
We have a number of systems we employ for this type of work but its only around 1 in every 4 jobs that we are actually polishing marble/travertine/limestone/terrazzo/concrete. The other 3 are cleaning and sealing of victorian tile, sandstone, slate, porcelain etc etc.
There are a number of courses available from NuLife, Tilling Logistics, IICRC, Alltec, Stone Doctor/Crawshaws and a couple more I cant think of off the top of my head.
I personally have done the IICRC course (2009) with Keith Robertson, The Stone Doctor (1999) course at Crawshaws and the Nu-Life (2010) course with Mike Philbin. All of them have been excellent even after having done this work for 15+ years.
I dont know the content of the Cheetah Pad course that was held. I would imagine it was focussed more on the polishing side of things but I may be wrong.
I would recommend looking at one of these as your first venture into the stone/tile market.