There's been a recent uproar about British Airway's Executive Club miles being converted into Avios miles, as a huge devaluation. Previously, BA miles could be used very flexibly by using say 25k points for a one-way travel from SFO to Bangkok. You could choose Hong Kong as a "stopover" and spend a week there, for no extra charge. In this way, you are getting two long flights for the price of one.
With the conversion to Avios, this is no longer possible. Avios points are based on how far you are flying, and will cost you more or less points based on their mileage grid. However, there are some flight segments that will benefit from this.
I had to book a flight from STL to NYC about 5 days prior to travel. Searching the usual flight search engines showed prices around $200.
My options were:
Membership Rewards: $200 * 100 MR/dollar * 80% = 16k MR points.
AAdvantage miles: 12,500 miles + $75 fee
Avios: 7,500 miles
Flight 2: NYC-LAX
Membership Rewards: 32k MR points
AAdvantage miles: 12,500 + $75 fee
Avios: 12,500 miles
So even though the valuable stopover loophole was closed, and that longer transatlantic flights will likely cost more, they can be used pretty flexibly for short-haul flights that are bought a few days in advance!