I have traded and resold some Thomas SSL's. They really aren't bad machines. Pretty plain jane, Kubota engines, easy to run. It is really difficult to resell them though. Most people have'nt heard of them, and like keltic said, small market share. They haven't had a good dealer base either, but where they have a commited dealer, they do okay.
Research the local resale market. Initial price minus the resale price (plus interest, insurance, taxes ect.) equals your owning costs. If the machine is $20,000 new and worth $10,000 in 5 years, your owning costs (in very simplified terms) is $10,000. If a bobcat is $25,000 new and worth $17,500 in 5 years, your owning costs are $7,500. So the $20,000 machine may appear 'cheaper', the $25,000 machine will actually cost you less in owning costs. (operating costs are another thing)