The RAF need the capability to practice at low level and at the high speeds involved.
Simulators are not a viable solution yet as not only are they restricted in terms of G forces but they are not up to a standard where the flight simulation and weapon delivery can be packaged in to one. I accept that they are fantastic for commercial training but the military is a completely different area.
Currently, I believe, the RAF is the only force worldwide that regularly participates in low flying training to an operational level and therefore are world leaders in the field. It is a required skill and this has been proved. Americans may have good medium level armorment but how many times has this gone wrong in comparison to the traditional shoot what you can see ? The americans come away from conflicts having lost more men to friendly fire that the enemy mainly due to technical faults with their high-tech weaponry.
The traditional low-flying must be kept and to limit it to 250kts is ridiculous, the manoeuvring speeds of these aircraft are too high, 250kts, although flyable, would not provide the required training.