I have been doing Mephistos and Azeds for about the past 10 years. It still takes me a few hours, usually, to complete a Mephisto, and a couple of hours for an Azed (apart from a Christmas or Easter 'special' Azed, which are REALLY hard and I lose nights of sleep over!!! e.g. last Xmas's one required an understanding of the 'Playfair' Enigma code).
Wish I could get a 'commended' in the clue-writing tie-breaker which is sometimes required for the Azed.
But I have won prizes twice in both over the past years - the odds of winning must be much higher than in other cryptics.
But winning a few prizes in no way covers the cost of the postage for all the cryptic crossword grids I send in!!