I didn't purchase a MAP for the first time in 2016, and haven't missed it in the slightest.
I always got good value out of it in the past. Around 7-8 trips to Towers, a couple to Thorpe and the odd one to Warwick Castle, London and Chessington usually in a year. Along with discounts on hotel stays (and discount on alcohol consumed at the hotels, which possibly technically paid for the annual pass by itself!) But trips became increasingly more frustrating with the obvious cost-cutting, lack of customer service et cetera. Although I was still technically getting a good deal out of the pass, the enjoyment factor had almost completely died for me - with the notable exceptions of Scarefest and fireworks.
This year myself and the small group of friends that I've visited Merlin parks with in the past decided to invest the money that we would have spent on an annual pass on a 3-day trip to Phantasialand instead, and it was 100% worth it. We had an absolutely incredible time at a vastly superior theme park which we had never visited before. Everything about Phantasia juxtaposed what we'd experienced at Merlin parks for years previous, and reinforced the reality that the standards in the UK are beyond unacceptable for such major theme parks.
I've also punctuated the theme park open season with trips to UK parks which my Merlin Annual Pass has caused me to neglect; two visits to Drayton Manor this year, and one each for Lightwater Valley and Blackpool Pleasure Beach. The standards really aren't that dissimilar and, for around £20 each, they're surprisingly good value. The burden of the Merlin Annual Pass is the need to get your money's worth and consequently visiting the same few parks over and over again. I feel released from that burden now.
Granted, I did visit Alton Towers once this year, but only because I was offered a £10 "share the fun" voucher by a friend who fancied a trip. I had a decent day there still, but it just reinforced my utterly indifferent feelings towards the place at the moment... I don't plan on returning until SW8 opens.
So, in short, I won't be investing in one this year. I'll be spending my "annual pass fund" on a long weekend at Liseberg this year. Generally I would encourage others who've become disillusioned with Merlin to do the same; spend the money on a European theme park trip or visiting some of the "smaller" UK parks, you own't miss your MAP as much as you think you will.