Test prop is great, especially if you combine it with enanthate or cypionate.
I have done this at the begining of cycles. The test P is to get it off to a quick start, so you start the P and E on day one, yes its lots of test. I just went ahead and kept running the prop for the first 10 weeks of the 42weeks (then just E actually I was using cyp) though cause it was so good.
Its kind of like putting nitrous on a big block.