Brother I send payments all day long anywhere from .5 BTC up to 3 BTC at a time, always use 10,000 satoshi for transaction fees. I have not had a 10 to 15 minute transaction in over a year, 20 minutes is the fastest I have seen in a year. average of 35 minutes longest 2 hours and 25 minutes.
That's strange can you provide a set of tx ids
My transactions tend to be in the standard 10-30 minute range of blocks even with fees usually I haven't sent recently seeing as its being tested but since you mentioned over a year I find that suprising.
That said I can understand your irritation seeing how time sensitive transactions are a pain like Bitpay with its timer...