Love my mini slanted. Quality is the same high quality as any other mesa cabs I own or have owned, which includes other 1x12s, the recto 2x12 and 4x12.
It is boxy sounding, but that's the nature of small closed-back cabs. Since I'm only really using mine at home, I traded down from a 4x12 and don't miss it at all.
It's lightweight and sounds killer for what it is. Comparing directly to a 2x12 or 4x12 yes, it will usually come up short. But that's the compromise you make to go down in size/weight. I love that when I do take the cab anywhere, the whole rig is an easy one-handed carry. Minirec in the bag over the shoulder, and cab in one hand. Guitar in the other hand. It's been a long while since I've had a whole rig I could carry in one trip!