Rv8Builder:
Low and slow? Burning tons of unnecessary fuel? You're kidding, aren't you, mate? The IDLE POWER descent profile for the Boeings around here is very roughly the following:
80nm... FL200... 300KIAS
60nm... FL150... 300KIAS
40nm... FL110... 300KIAS
35nm... FL110... 250KIAS
20nm... 5000.... 250KIAS
So at 40nm to be on a normal idle power glide descent, you want to be around FL110. Roughly. So, as you can see, FL190 as about 8000' above profile. That's a fair few extra track miles or a fair bit of speedbrake to get back onto profile....