Reed relays have a much faster switching time than armature relays. I purchased a few reed relays recently and used some to make a toggle flip flop. The relays have a switching time of about 1ms. This video shows the toggle flip flop operating:

The reed relays used here are double pole single throw 5V relays with a 500 ohm coil resistance. Designing a toggle flip flop using single throw relays was a challenge.

The photos below show that the toggle flip flop can be toggled at a rate of 625 Hz (the oscilloscope shows the output from the toggle flip flop - a 312.5 Hz square wave).

This has some relevance for DIY 3D printed relays: single throw relays are simpler to construct and have fewer design constraints. There is only one contact to worry about, and when the relay is in the open state, no part of the relay is under stress, so there is no opportunity for stressed parts to creep when the relay is off (a potential problem if using PLA).