In my opinion, I wouldn't purchase anything by JCB. I worked with a company that had two combination units, and both had serious issues throughout their life.
I have a 2004 Bobcat S300, and it has been fantastic. That said, since Doosan took over Bobcat, I wouldn't consider them. Again, my personal opinion from things I have learned from reliable to me, sources. I have heard of serious engine problems, and they recommend a replacement vs. a rebuild. I have heard of a lot of other issues coming from workers of a large company that buys a very large number of units.
When I am ready to buy a compact track loader, I am pretty sure I will go with Kubota. In my area they are very popular, and easily sourced for parts and service. When I am ready for a mini excavator, I will most likely go with Deere or Kubota, but I will also consider a CAT.