We all do it I expect, trying by all available avenues, to accumulate as many miles as possible but I'm starting to wonder whether it makes sense, for us at least, though YMMV.
We channel all spending to miles-earning Amex cards.
We pay for extra miles via Miles Booster
We chase tier points to retain Ag status which offers nothing else but does boost miles from flights
We pay extra to fly in the top fare codes to use our miles to get Gs
We re-arrange our dates to fly when Gs are available (not always easy for us, most of our flights are to visit family in NY so we're juggling our own dates, son's frequent business trips, their family holidays, etc)
But just a minute, how about this scenario:
If we use AMS/DUB trick, we can fly on our own choice of dates, in UC, for several hundred pounds less
We don't need to pay for Miles Booster
We don't need to chase tier points
We can channel our spending on (say) an Amex reward card or cashback card and get something back instead of miles
Looked at that way, it seems a no-brainer so I must be missing something or else we'd all be doing it and no-one would be chasing miles, so what, dear
V-Flyers, am I missing? 
We channel all spending to miles-earning Amex cards.
We pay for extra miles via Miles Booster
We chase tier points to retain Ag status which offers nothing else but does boost miles from flights
We pay extra to fly in the top fare codes to use our miles to get Gs
We re-arrange our dates to fly when Gs are available (not always easy for us, most of our flights are to visit family in NY so we're juggling our own dates, son's frequent business trips, their family holidays, etc)
But just a minute, how about this scenario:
If we use AMS/DUB trick, we can fly on our own choice of dates, in UC, for several hundred pounds less
We don't need to pay for Miles Booster
We don't need to chase tier points
We can channel our spending on (say) an Amex reward card or cashback card and get something back instead of miles
Looked at that way, it seems a no-brainer so I must be missing something or else we'd all be doing it and no-one would be chasing miles, so what, dear

