If increasing timing flat out in a linear fashion across the rpm band, you're going to get the same effect as a larger pinion/smaller spur. The advantage of a nice speedo comes in where you can increase timing at a certain rpm, so you still have your torque of low gearing, but get the top end timing advance. Not sure if your speedo can do this like a Tekin can, but I do believe the Mamba Pro can. To simply answer your question, increasing the timing from 0-top rpm is the same as gearing up, but do it only after a certain speed and you can do even more timing without sacrificing any low end torque and the consequential increased heat.