G,Day Pete,
I have gone with a smaller machine on wheels (226BII) but I still bring in a guy with an RC30 on occaision. I don't know the details of your conditions nor do I have the owner operator experience with CTL/MTL. Here is my take on things:
Sometime back an well respected operator (Hardscape/Landscape in US) of Cat tracked machines put some numbers together and came up with an additional operating cost of $5-$7/hour over a wheeled machine. Couple that with much higher purchase costs and and questionable re-sale value.
Now if I was fixed price contracting to commercial builders the machine which does it fastest makes you the most money...no question. Additionally any tracked machine will be more productive than wheels when it is soft underfoot.
When it come to hourly hire, working for the Jones etc they don't seem "more productive, lower ground pressure" etc in order to justify charging $10/hour more. All they see is ther hourly rate. A Bobcat is a Bobcat!.
That said, many builders are cottoning on to the improved performance of a CTL/MTL over a wheeled machine. There are many restricted access and difficult situation jobs that, barring manual labour, can only be done with something like the RC30. I personally love the concept but you have to have the niche or the right market to make it pay.
At present I am bidding a job;
50 metres of 1m high stonewall, 1/2 with steel fence atop and half with piers and timber infill.
4 x 1200 x 1200 concrete soaks and plumbing to new house
12m x 6m poured limestone driveway
Stone letter box and driveway piers
About 100m3 to shift around on site and probably 40m3 to go away.
Compaction, backfilling, 80m2 of verge to tidy up, reticulation and topsoil to install (25m3).
Now I'll go with the 226 and the 3 tonne mini-ex.
An RC 30 would be wonderful on that job for quality of finishing off around the house but...But!: I can't carry pallets of stone like the 226 can, it can't load out 10m3 into a 6 wheeler in 14 minutes and it can't shift the dirt anywhere near as fast. Would it be good - Yes, will it make me any money....in this situation NO!.
You need to charge more
You need to look after it
You need to have the market niche
I can only get 1 1/2 of the above.
Thats what my research leads me to....at this stage...maybe next week I'll regret it:Banghead