What size COMPACT TRACK LOADER best works for MX TRACK

I will add my 2 cents.

I have 7 machines, 5 Cat, 1 ASV and 1 Takeuchi.

Over 20,000 hours in skid steers and MTLs. My Cat 299d2 XHP is a beast. Plenty of push and does everything well. Too many sensors though and the electronics are a pain. For building tracks, they are quick and good for bulk work. For finishing jump faces and whoops it can be hard to see the cutting edge of the bucket. They are a big machine and take a bit of getting used to. If you are not experienced you can stuff up your job quickly as they will dig into a jump face and before you know it you have undone the last 15 minutes work. 

Cat has a good global network and parts are quick turnaround. If you are somewhat mechanical you can do most things yourself. The newer electronic stuff can be a nightmare if sensors start playing up. 

A good friend has the Takeuchi TL8, I believe it is the best size and has a better line of sight for maintenance but not as quick for bulk work. The Cat 259 is the same size. I liked the TL8, will be my next purchase.

I rarely use my ASV as it doesn't have an enclosed cab. Take note of the guy's recommendations about the undercarriage. It is more comfortable but very expensive to fix, lots of moving parts. 

I have driven the 247''s, never owned one though. Great for final trim and cleaning up. 

4000 hours is the magic number where you can easily get caught with issues. The engines are pretty good on all the machines these days. It is usually the hydraulics that start to give you problems.  Stay away from any machine that runs ad blue. A machine of that vintage with adblue will break your heart if you have to fix it. My N02 sensors failed on my 299 at 1000 hours. Cost me $11,800 to fix.

As a contractor, I have never kept a machine for more than 3000 hours.

A Bobcat T590 on tracks would be a good compromise for you I think. It will do a lot of track and finish work. Wont move big piles of dirt, but will be great for track maintenance. A pretty good choice in my opinion. 

I don't have as much time in Bobcat CTLs. I've only run a T300 ( 2009 ish I think was when it was made) , and  the controls on it felt sluggish compared to the Cat and Deere . Even the Older Cat stuff was fast and smooth.   I have not run any of the newer Bobcat CTL's though.  I have run newer excavators from Bobcat and they were nice and responsive and felt more on par with other brands.  I think the T590 is a similar size machine to the 247. Around 60HP.  I have not heard of many people having issues with Bobcats. The most common one I've seen and heard about is a wire getting damaged or solenoid that stops the arms and bucket from working.  I've seen that come up as I have been searching myself for a CTL and trying to avoid buying somebody else's problems.   

  And the guy that made the point of bigger machines being able  to make bigger mistakes, I agree. With a 80HP or less machine, they have to work a little harder to move the dirt. But that can be helpful when doing fine grading if You are not running a machine often or learning. It was one of the things I also noticed in that Deere 333 VS the lower powered machines I had used on my property before.  With the smaller machines I could slowly push up to a stone curb and stop when I felt it . Not doing any damage or  moving anything that I did not want to move. With the stronger machine I could rip the curb up and not feel much if any resistance. I learned after I had to fix the curb.   I like the extra power. But for somebody that is very new to operating. The lower powered machine let me get closer without worrying about ripping the curb out. So I agree that all the power might make fine grading harder to do for newer operators.   

Hell yeah! Thats a nice machine!! Should be perfect. 

A machine I havent seen mentioned is the Case Minotaur DL550. It has a lot of lifting capacity as a CTL, but also have a true bulldozer adjustable blade setup. The price is a little spicy though and honestly for the same money I can get a new takeuchi TL12v2 and a used D3 dozer. Just another machine to consider if you have the budget

https://youtu.be/ycqFT47YuQg?si=tyYDn95WkzaUo7he