The big problem is that ReactOs is not enough stable yet and have numerous crashes. I have tried to install Lazarus in several versions of ReactOS and Lazarus sucessfuly. It compile ok for little things.
I have run it virtualized under QEMU with KVM and require little resources. It could connect to network with the new network driver.
It uses its own adaptation of Wine and one of the things that happens is that images in buttons are reflected, they say its a problem of wine but i think that actual wine have this corrected but ReactOS not.
In ReactOS are working hard and this effort make it more stable each year. I have to try newly with recent versión of Lazarus and some of the daily build and see how it works now.
The last i have tried is this, i was able to run in real hardware with a ten years old computer:
https://sourceforge.net/projects/reactos/files/ReactOS/0.4.0-FOSDEM2016/Best Regards.