Perhaps I'm wrong but I get the impression that you do not understand the difference between a true Garden Tractor and a Lawn Tractor.
Lawn tractors are designed expressly to cut grass but some of them can also blow snow, blade snow and pull light lawn carts. The components chosen to build lawn tractors are all "light duty". The frames are usually stamped steel that are not designed to handle the stress of being used on rough ground that will cause them to flex and eventually crack to the point of failure.
One of the weakest components is the hydrostatic rear axle units which are often "factory sealed", meaning they cannot be serviced. When they fail, the only option is to purchase a complete trans-axle unit which is often worth far more than the current value of the complete tractor in good running condition.
These machines are built to meet a certain "price-point" that is normally LESS than $3000.00. True Garden Tractors will cost $8000.00 and up, depending upon the options and attachments selected.
I can give you more reasons why you should not buy a Cub Cadet than reasons why you should. By and large, the Cub Cadet brand is no longer considered to be a quality product and hasn't been so since the 80's.
Cub Cadet is now just another brand name owned by MTD. At one time, Cub Cadet was owned by International Harvester and they turned out a high quality product. Today, the former quality is apparently no longer there, so I would advise you to steer clear of that brand. MTD/Cub Cadet no longer offers a Garden Tractor. The last model that had that description was the 3000 Series but when it came to quality, it did not come close to that of an X-700 Series Deere, Simplicity or Ingersoll 4000 Series.
I don't know what your budget is but one of the very best bargains in the used garden tractor world are the Ingersoll 4016, 4018 and 4020 models. If they have a PS after those numbers, then they have power steering. They can be had with a true CAT 0 three point hitch. Unlike most tractors, these are hydraulic drive, not hydrostatic. They utilize a separate pump and motor which makes repairs both user friendly and inexpensive by comparison. Operation is quite similar to that of a hydrostatic drive tractor. A single lever controls direction and ground speed. The trans-axle has two ranges. One for work and one for travel.
The interchangeability of attachments is unparalleled by any other brand. Hydraulic implement lift is standard. A rear mounted hydraulic PTO valve can be added at any time which will allow you to make use of certain implements made by Ingersoll and formerly by J. I. Case who used to own the brand. The quality is legendary as is the ease of working on them. Parts are not a problem either as there are several dedicated dealers who are eager to ship you anything you need the very next day.
One thing you will learn to love is the 16 inch rear tires instead of the 12 inch rubber used by everyone else. The ride is quite superior. The front and rear axles are made from cast steel. The frames are welded together using structural steel. The mower decks are also made from steel plate that is bent and then welded together instead of being stamped in a punch press.
Mower decks come in 44, 48 and 60 inch cutting widths. The Case and Ingersoll models meet your criteria of being "more substantial and more tractor-like." All you need to do is to spend some time discovering what they are all about and there are several forums on the internet that are dedicated to them.