That was great advice. Figure out your budget. How old of a machine do you feel comfortable with? You can't 'convert' a wheeled machine to tracks easily but you can ADD over-the-tire tracks which many guys do and like. But that's an extra expense. Sometimes ya see some used ones that are reasonable. It's a good middle ground. Tracks in general are higher maintenance and shorter-lived. There are more rollers and bearings to fail, and the main drive wheel teeth wear (become sharp) and are expensive to replace. So if you found a used track machine you were interested in, you should have it carefully checked out by a knowledgeable outfit b/c otherwise it can get expensive. The track machines in general have a lot more pushing power, sort of like a dozer. But do you need that amt of extra power. They are better in softer ground. From a buying perspective, the ideal situation would be if you stumbled onto a machine which had tracks and drive sprockets replaced fairly recently. As a hobbiest, you're not likely to put on a ton of hours like a contractor would and they would probably last you a long time. That said, prices on replacement tracks have come down too. Skid loaders with tracks usually have a higher load capacity too due to the tracks sticking out just a little further. But it makes a difference. I would say they may be even a little safer.
Pins and bushings wear too. You'd want to check these on a used machine, especially the lower bucket bushings. A couple pins/bushings needing replacement aren't too expensive, but if you had SEVERAL to replace, a guy could drop a grand pretty quick.
Then you should look at things like hand controls vs. foot controls for the bucket. Foot controls guys are always going to say THAT'S the way to go ...hand controls guys like hand controls. Most have pretty much gone to hand or joystick controls. People who operate foot controls get sore shins after a while. Plus it's more to trip over getting in/out. Electronic joystick controls are nice, but there again, more stuff to fail ..and when things fail on a skid loader, it's always expensive if you need to take to a shop. Older machines didn't have computers and were mechanical. By now they have the electronics pretty well figured out, but earlier machines may need a keen eye to inspect the electrics. I would look at machines which have good ergonomics, comfortable and easy to get in/out of. To me, that's really important since ya do it a lot. The Gehls have really low profile loader arms which make side visibility greater. Low step-over entrance threshold too. One with a/c would be nice too ..and a front door (quieter). Gehl, Case, Bobcat, Deere, Cat, they all make good machines. Start with your budget and work back from there.