I shared a MB BubberSher bat with friends couple of years back. It's a decent bat - medium size edges, concaved profile, spine running till the toe, mid to high sweet spot, curved face something like f4.5 gm models. As you can see from other posters the profile consistency isn't a strong point of MB. Profile could vary from bat to bat very easily.
Performance - Bat didn't ping well of the mallet, however after knocking and when we started playing it was as good as any other grade 1 english willow bat. The best thing of the MB bat is the pick up and balance. The bat weighed about 2lb12oz, but felt like 2lb10oz in hand.
Reliability - Toe is not a strong part of this bat. After 12 months of abuse and digging three successive yorkers the bat gave up. It cracked from toe to about 2 inches up the blade (on the back side). I had it refurbed and used as a practice bat and in wet conditions. I will get some pictures for your reference.
MB has more fakes than any other brand on eBay. So i would recommend buying from a well known retailer. The newer models of MB Malik have a bar code system and that would help check if a bat is genuine or not.