When asking about Ashgabat...I basically describe it as what would be created if Las Vegas and North Korea had a child.
You have the hot dry desert and massive video screens, lights, gilded roofs, gorgeous facades like in Vegas, with the omnipresent stench of government repression, like North Korea.
THe individuals we met all over Turkmenistan were EXTREMELY friendly and nice, just don't bring up the government at all. We stayed at the Hotel Ashgabat (old SOviet hotel in the center of the city) for two nights and found bugs in our room (recording devices...hotel was actual roach free from what I can see!).
The whole thing was a great experience and totally worth it. Go up to Darwaza to the gas crater and continue on to Konye-Urgench and then into Uzbekistan. You can still hit Khiva and then skirt southeast towards Bukhara.
We had planned an afternoon in Bukhara, but it was so amazing we ended up spending a couple of days there.
You'll love both countries and will definitely have stories to tell after the ferry ride