The Laser 310 is only an improved version of the Laser 200/210. But both computers stay compatibles with each other, for software and hardware.
The Laser 300/310 has a quite bad typewriter keyboard, the stroke being quite weak. But this is not surprising for a VTECH product... Apparently the keyboard is directly mounted upon the old mechanism of the Laser 200/210 rubber keyboard, which explains a lot of things...
The Laser 310 has more memory than the Laser 200/210 : 16 KB. But strangely enough, some games sold for the Laser 200/210 with the 16 KB RAM extension won't work with the Laser 310. That's because the Laser 200 has 4 KB, so a bit more than 20 KB with the 16 KB RAM extension, whereas the Laser 310 has only 16 KB...
Finally, the last improvement is found inside the machine itself : the conception is far more integrated and the its quality is better.
As usual, Dick Smith Electronics sold the Laser 310 in Australia and New-Zealand under its own brand where it was called the VZ-300.