[GeronL]

Like an Ion engine it probably takes forever to build up speed

[Boogieman]

That all depends on scale of the drive. These demonstration models probably wouldn’t budge a Prius, but if you have a big enough magnetron and nuclear reactor to power it, the acceleration should be much greater.

[InterceptPoint]

Like an Ion engine it probably takes forever to build up speed
++++
Assuming it works this is true. Ditto slowing down.