Dagu Rover 5 chassis robot demo

Greetings.
I've been working on modelling and control of this platform for a while now and I have a question to ask if it is possible. The encder pulses seem to be quite long or slow to be able to get a good PID control from them. Has anyone tride this? have you been successful? can you share with me the method you used for speed measurment? I'll be more than thankful for any answer.
Cheers.