Tramadol vs Neurontin?

I have Rheumatoid Arthritis and have been taking Tramadol for my pain. My body is becoming immune to it so I am having to take more then is prescribed for me. My doctor switched me to Neurontin. Do you know what works better for pain? Can I mix the Tramadol and the Neurontin? Does the Neurontin give you the feeling like narcotics such as Percocet or Vicodin?