My 2 cents......I would avoid a track machine, but that is just my perspective. There are a few things you need to consider. If your looking for a track machine in that hour range, then it will probably be due for some undercarraige work, this = $$$$$.
Now, I have told many folks you would be hard pressed to give me a tracked unit and here is why. Tracked units have an overall higher cost of operation than rubber tire units. They go thru drive motors, tracks, and undercarraige parts quicker than you would expect. To offset this, one would need to keep the machine working at or near full operating rate, and when doing side work the tendancy is to cut the rates to kick start the work coming in. Now, if your projected revenue can justify the extra overhead and/OR you plan on being the only operator (things will last longer this way), then it might be worth it if the work you plan on doing trully needs tracks. Tracks can really be the enemy if you do any volume of work that has you working on concrete/asphalt.
As far as brands, I'm a bobcat freak, if they say imitation is the highest form of flattery, then Bobcat is flattered regularly I feel. The Takeuchi brand is nice, but all the ones I have seen have the joystick style controls and I know of many folks that have problems with that, even on the Bobcat brand. The Bobcats however, I know you can get with the old style controls. They are simpler from my perspective and are more in line with the KISS principle.
I would consider other brands if the price was right and I could get parts/service when and where I wanted. The machine that intrigues me the most is the one folks expect the least though. ASV makes several track machines that some compare to CAT knockoffs. They have a widetrack model that looks to be along the lines of a small bulldozer. That machine impresses me.
I can't speak to the value of other brands, but if you find a used track machine under 20k, it probably needs work, or will soon. Something else you might think about is a rubber tire unit with OTT tracks, or a Loegering kit.