I don't see the need to take an FTP test any time soon. TrainingPeaks sends me alerts when they think I should increase my FTP based on actual rides, which is good enough for my purposes. I bought a few used books from ebay including the Coggan and Allen book and there is plenty of supplemental info available with GC to explain what the numbers mean. So far, I like having a power meter much more than I thought I would.