I've megan EZ streets as well and I like them a lot. I can only compare them to stock but as botbullet said they're very comfortable on the soft and medium settings which is good for street driving. I was running mine on the hardest setting, but now the highway I take to work is under construction and it's just ridiculous. I wouldn't say they're "track ready" though, there's a few posts around on miata.net and clubroaster of people taking EZ streets on the track and they basically become mush compared to a real coilover set up.

The Flyin' Miata Vmaxx XXtreme (I feel stupid even typing that) package with the sway bars and adjustable dampers would probably be an excellent starting point.

 

I'd only go with front fm sway bar or a rb front and fm rear.