What is everyone at your local track running? The Tekin RS is the most popular ESC Localy but there are a few of us running LRP's, in superstock (13.5) buggy most are running the cheaper competition spec, I am running the stock spec just because its what I have. I love the feel of mine with my reedy 13.5, the low end power feels like running mod buggy and the LRP is super smooth compared to how my tekin felt (I havn't run a tekin since version 208 though and I've heard they have gotten better) the downfall of running the LRP is that there isn't a lot of help on setting it up, I kind of have to figure things out on my own, which is where you would have some advantage running a tekin here because everybody and there brother knows the software and can give you help figureing out how to set the ESC to suit you.
Tekin's are the cheapest GOOD boosted esc that money can buy IMHO, customer support is excellent and I've only ever seen issue with 2 ESC's and tekin had them replaced within 2 weeks of the original complaint. I've seen no other company with support like that on electronics.
Castle's Mamba Max Pro is a big esc and you will have trouble fitting it into your buggy, they also have some softare issues with the esc hesitating on takeoff that I don't know if they have fixed yet or not.
Speed Passion ESC's are okay but they as well were having software issues a year or so ago that would turn the boost feature on and off because they thought the voltage in the battery was droping below cut-off when it wasn't. They are just really power hungry. Your okay if you have a good newish 50c+ lipo. I've had issues with their customer service however.
I dont have a whole lot of experiance with novak. There brushed stuff is great but I had a GTB go bad on me 2 laps into a mod 4wd buggy race that left the ESC in full throttle mode with a 4 turn orion brushless motor. The car turned itself back into a kit after driving itself through the pit area and I never ran another Novak. (and yes it was the esc and not the rx, the solder joints went bad inside the esc and bridged two connections, I still had steering and was able to avoid hitting anyone)