The thing about GM transmissions - they will last 220,000 miles if you take care of them. They are not labor intensive. Change oil and filter every 30K miles. Do not ever flush no matter how much the service guy insists that you do. Don't do it, it just flushes all the crap and dirt all through the trans.
The weak points are the bands in 2nd and 3rd and the plastic actuators. Not meant for heavy towing although I towed my race rzr and trailer all across the west and have had no issues. When you bump up horsepower, you need to add a HD Sunshell and aluminum actuators. Eagle bands are more durable. $1,200.00 in parts and labor and your trans will be fairly bullet proof. Two killers of an auto trans, the radiator milkshake and heat.
Best and most educational Transmission site ever:
https://transmissioncenter.net/product-category/gm/?product-category=4l60e
If your trans breaks there is a reason. Abuse and lack of maintenance are the two most common reasons.