I still occasionally make a MRB Beer. I use my own hops and amp up the IBU's
I make fairly decent beers however they are only made with extract. None of them are made with "corn sugar & maltodextrine" thats in the booster pack.
Many people compliment me on them and they are surprised as to how good they are after tasting them. Most if not all are shocked when they learn its from a MRB kit.
Most if not all MRB beers fall into the session style category. Usually less than 20 IBU's and under 6% ABV
On the equipment side of things, I don't use the keg as a fermentor. I use 3 gal carboys fitted w/ an airlock and do the 1-2-3 thing. (1-week Primary, 2 week secondary, 3 week bottle) The MRB keg is relagated strictly to bottling duties. I also follow up 1-2-3 thing w/ cold conditioning my beer for 3 months before drinking them.
My MRB brewing fills in my supply gaps as it takes less time to make them.
I will say that I have made more so-so beers in the 5 gal size than I have with MRB. The root cause has been from mistakes in developing my own recipes or buying 5 gal kits with old & lousy ingredients.
MRB is not a bad start. The thing I like the best about them is the size 2.25 gal. I'm really the only drinker in the house and I don't drink very often. 5 gal batches last too long for me. I get tired of them.
I think MRB gets bad press mostly from people who are ignorant to proper sanitation and aging requirements. Not to mention brewing water quality.
That's just my opinion...
Ignorance example: I had somebody ask me why my beers are always carbed good and their's were not. I asked them about how much sugar they used. Answer: 3/4 cup. Not 5oz. They were measuring out a 3/4 cup out of the 5 oz pack then throwing the rest of it away that came with the kit.
Another duma$$ example: My BIL made a MRB Beer fermented it for a week then went to bottle it. Before bottleing, he said it tasted like crap, so he dumped it down the drain. He also commented that it was kind of flat!!!!
Often ignorance is what makes bad beer!