Just spent ten days in Niger, driving alone with my own 4x4.

I had the visa in Ouaga at the consulate, easy to get, two days, 20000 CFA.
Coming in from Dori in northern Burkina, I drove straight to Niamey.
Easy drive, easy and relaxed border crossing, good road, not many cars, several checkpoints. In Niger you must have your docs in good order, laissez-passez, insurance etc, much tighter control than Mali or Burkina. They still haven't caught on to the use of a ready made fiche so some checkpoints will take time, but many will just wave you through.

Spent a couple days in Niamey, then drove to Agadez, with a few short off road excursions. The goudron is fine until Tahoua, then it is terrible the remaining 450 kms to Agadez, esp Tahoua-Abalak, with holes big enough to swallow your vehicle where the roadside has caved in.
They have started making new pavement around Ingall, and locals say the French (Areva) will make a new road all the way to Arlit.
Agadez was surprisingly relaxed. Very few tourists though, only a few stray travellers. More NGOs and miners, travelling with armed escorts. And a few men in uniform, both French and US.
You used to be able to climb the mosque with a guard, offering a good overview of the city. Now you need permission from the Sultan of the Air; according to locals that is because you can see the activities on the American drone base on the outskirts of the city from there.

There was a US/French film team in town, shooting a movie in tamasheq with amateur touareg actors.
Mdou Moctar Stars In A Tuareg Remake Of Purple Rain Okayafrica.

Going as far as Agadez was no problem, no questions asked, just drive as you wish.
Now in Agadez I asked permission to drive around. I could go to the Iferouane festival without an escort (wish I had had the time to do so). And the Gerewol/Cure Salée in September is in Ingall on the main road, so no problem going there.
But driving around in the Air would require an escort. There are still mines, and general insecurity.

As for going to Arlit (250 kms), I had four responses, depending on whom I asked:
-no problem, go on your own, several checkpoints!
-you need a military escort $$$!
-you are a tourist, no way they will let you through!
-50/50 your vehicle will be stolen, or worse!

So I didn't go to Arlit.
Also asked about venturing further east, but all destinations would require a military escort for which I would pay.

But Agadez itself was fine. People still a little worried after the suicide bombing last year. I don't see a real return of tourism in the near future.