The non-slip rubber backing keeps the playmat from shifting during use
There are so many +1/+1 counter synergies these days that its incredibly easy to make an oppressively powerful deck with that strategy, and I personally dont like the mental energy required to keep track of all the various triggers those strategies accumulate on the battlefield
At the moment, Laboratory Maniac is approaching $7
If you can ramp up to his Emblem, you can be hard to slow down
Offering access to the entire color pie, Wizards is typically very careful when it comes to printing these cards
So, you shuffle all the cards back into your library, you draw a new 7, and then you put a number of cards from your hand on the bottom of your library once you decide to keep the hand