I've been given "go" and "no go" pills by Uncle Sam, and while they lean heavily towards Zolpidem in that context, I was lucky to only ever use zaleplon a few times and never touch Zolpidem. Frankly I don't think I ever would either.
Zolpidem -> Almost always a nightmare to deal with. God forbid there's a reason to need to wake up early (contact/somebody doing something retarded/etc), the guys who took Ambien would be literal zombies. Less helpful than zombies. Actively unhelpful, confused, incoherent liabilities.
Zaleplon -> You could wake right up and never think you took anything. Downside is I could easily fight through it if I wanted to, didn't HAVE to sleep, and without fail I'd wake up at exactly 4 hours every time. Could easily fall back asleep if needed, but it's not going to keep you out.
Have zaleplon stocked up that I will use on rare travel occasions, and am skeptical of anything GABA related in general so make that a very rare use case, but it is by far the superior drug in that class IMO.