I run the novak gtb and 6.5 motor in my T4. I absolutely love the thing. Just gear it and go have fun, have more fun, and keep on having fun. I still have a comm lathe and brushed motors but I don't see the point. All I have to do with brushless is oil the bearings now and then. I race on a slick track and the speedo is nicely and easily adjustable to suit your needs.
My true love in rc is nitro and always will be. But I'm thinking of getting some lipo batts just for the extended runtime and not practicing with my nitro cars anymore to save wear on the engines. The 6.5 motor is every bit as crazy as my novarossi engine in my GT and that's saying something