For performance, you can do some speed tests. I don't know, really - and I would prefer whatever is more readable.

One advantage of STORE - which makes me use it every now and then - is that the same value can be stored to more than one place. Here is an example where this can come in useful:

* I don't like the repeating condintion in the following:
with ThisForm
  TxtOption1.Enabled = goApp.UserLevel <= 2
  TxtOption2.Enabled = goApp.UserLevel <= 2
endwith

* Simplify, to avoid repeating the condition
with ThisForm
  store goApp.UserLevel <= 2 to;
    TxtOption1.Enabled,;
    TxtOption2.Enabled
endwith

>What difference is there between using:
>
>x=y
>
>or using:
>
>STORE y TO x