While I could dispense life advise and financial investment strategies, I will refrain. Personally, I like the idea of the Ergomo, and because of the Altimeter function I have thought of dropping the SRM and going with it. It is the only other power meter that would consider because I like having freedom of wheel choices. So, if you want to upgrade, reward yourself and sell the PT. You will probably be able to make it a not so expensive reward that way. However, if you are happy with the data from teh powertap and you have other rewards you would be interested in having, I don't think that the little bit of ino that you don't have (on board TSS, altimeter functions) are worth it. Go with something else that will make you happy.