NSF said
However, a turboprop is slower, less complex overall, does not travel as far afield and operates at much lower levels.
above FL100, being at FL250 or FL340 does not make any difference, the TAS/GS/MN high or low does not make any difference on straight lines between 2 waypoints (cruise are always flown in autopilot while we read the newspaper and we drink the coffee)..
Below FL100, speed is limited to 250 kts maximum, and this is always reached with an ATR or Dash8 in descent.
Approaching speed is more or less the same with a heavy TP or heavy jet.