Kame, I'm not sure what you're getting at here. Can the way a mini shoots be improved with an aftermarket barrel like you did? Sure. Does that in any way counter criticism of the accuracy of the gun as shipped by Ruger? Of course not.
Frankly I think the accuracy criticism of the mini, while true, isn't THAT big of a deal in the field. The issues surrounding the parts and accessories ecosystem, as well as the cost, is a much bigger deal for the typical not very picky shooter and/or one not using a precision aiming system.
As far as accuracy "contests" or whatever, clearly nothing is an apples to apples comparison. The LMT shoots better than what you were getting by a good margin, but it's also more expensive and eats expensive ammo. As with many things in life, you get more or less what you pay for.