"Realistically however it would take 90nm to get up and 90nm to get back down again leaving only 135nm for the cruise"
While we see figures of 4 or 5 percent fuel savings for the cruise portion (as a generic number), there seems little literature on the savings that winglets may provide for climb and descent.
Mr "E", can you perhaps elaborate on what approximate climb and descent fuel savings figures could be, and why they should be lower than cruise?