Andy,
When I imported my frame mounted backhoe, two chippers, and too many extras to write here, I did it directly from Jinma with no middle guys. Did I have problems...of course I did. Jinma took care of every single one of them for me. There were missing parts, wrong parts, damaged parts, etc and nearly all of these were minor. Since I sold some of the shipment I had to be sure I was provided replacements and whatever else I needed.
So..it all boils down to trust and reputation. I have my own company and I import from China. Customers trust us to handle their business from door to door and they are willing to pay for that. I found Jinma to be reliable in spite of problems and I would buy again. As far as other importers there are many good ones around and you can find them referenced on this site. they can take care of everything for you. I've been sourcing from Asia for almost 20 years and have a longstanding rule to not do business with anyone I have not met face to face and any factory I have not visited myself. I even visited the Jinma factory and posted pictures on this site.
If you Google Chinabest and others you might find reputation information. I would phone them and ask for references and phone numbers. A good middleman can save you money and headaches; however, on the other hand you can buy factory direct and save some money. If the middleman does not provide, with a proven reputation like sponsors of this site, tech support, parts inventory, etc, then one must wonder what they are really providing.
A middleman broker can save you $ because they have better factory discounts, freight rates, terms of payment, etc. At the end of the day when the tractor arrives and you have a problem..who do you call or email? If you buy factory direct from Jinma, you have a contact and they will help you.
If you want more info offline, let me know.