I'm a little late to this discussion but will throw in my two cents. First, let me say that I love Power-Trac's I have three (multiple properties). I also have a compact track loader (skid steer with tracks) and a mini excavator. As others have mentioned, it depends on what you want to do.
The Power-Trac has many advantages. But it isn't NEARLY as strong as a compact track loader (CTL) when it comes to pushing, digging, or lifting. I recently saw a guy dig out an in-ground pool completely with a CTL. Frankly, I was shocked. He is a subcontractor for the pool company and digs all their pools with a CTL. You can pick up a nice used Japanese made Takeuchi CTL for significantly less than the cost of a 1460 and it's a FAR better made machine.
The problem with the skid steer is stability. If you get it on a small slope and raise the bucket, it can turn over easily. A compact track loader is a little better but nothing like the Power-Trac. As with most machines, everything is a compromise. If you intend on keeping the 1850 for specific duties, and add another machine, I would choose a machine that complements the 1850's strengths and weaknesses. For example, I wouldn't choose a skid steer or compact track loader for mowing on a slope. However, I wouldn't choose an 1850 for the purpose of any digging. I would list out the most frequent and important uses for my current AND likely future needs. I'd focus on 80/20 and select a machine that would work best 80% of the time. For the other 20%, I'd make do or rent a machine.
For the record, of all the machines I have, including a compact tractor, my favorite machine by far is still the good ole 425. It does a LOT for what it is. It's relatively cheap (especially if you buy used), fast, fun, doesn't tear up the yard, versatile and brings a smile every time I use it. I'm not suggesting you consider a 425...just adding context for others reading this post.