Is this a reasonable design for a high-speed level shifter?
Although some consider this useless, I love this king of hobby projects, where you go down to the basics of electronics.

I think there is an issue with your circuit: V1 won’t raise instantly from 0V to 3.3V (and won’t either drop instantly from 3.3V to 0V). When it will be at 1.65V (and in fact roughly anywhere between 0.6V and 2.7V), both Q1 and Q3 will be on. As a consequence, both M1 and M2 will be on, causing an excessive power dissipation.

I think you should try to ensure that Q3 turns off before Q1 turns on and that Q1 turns off before Q3 turns on.