[modeless]

The window being one quarter? That still makes this more similar in practice to an ESPP than a standard four year RSU grant.

[nahname]

Yes, this would be for one quarter. I also agree it is quite similar to an ESPP, especially for the majority of people. I doubt many would be willing to allocate 80-90% of their total comp to ISOs.

[idontpost]

ESPP's have special tax rules that RSU's don't so the distinction is still very important.