it depends. when it's just common adopts (like; wolf, naga or an impopular species) or there's a lot of them at once, I prefer FC-FS, but when it's a rare and popular species, I prefer OTA, DTA, Lottery or Auction - not that I ever participate in auctions, I don't have enough points.
I'm not online often enough to catch most FC;FS designs, so I generally prefer auctions. If the bidding goes too high, well... at least I had a fair shot at getting it.
(The exception is when an artist updates their adoptable auction every single time someone bids. I find that massively annoying, especially since so many people seem to be doing it. I feel like I spend half of my time on DA deleting the same adoptables and designs out of my inbox every day)
I do agree on updating it every 5 seconds or multiple times a day to be annoying. I have a similar problem. I think that people should just be a damn adult and go look themselves at the price. It's YOUR fault if you forgot about it. lol