My own take on this
I have read lots of back and forth on this service and would like to add my own reasons for using it.
Using the British Airways Visa I pay my business rent, which generates just a squeek over 100k miles every 2 years. This along with the 2-4-1 companion voucher that such spending gets you, means we can fly to the UK every 2 years in CW for about $3,800 all in. This includes the William paid fee,(I am grandfarthered in) and the hefty BA award fees. A tad expensive yes, but I know of no other way the 2 of us could fly business to the UK and back for $1,800 each.
Hope this is helpful to others,
Sincerely,
Tattikat2