Tour company recommendations for Iran

I've wanted to visit Iran for some time, but have not been able to do so. It looks like now or never and there are openings in April with some tour companies. They are not inexpensive. Has anyone been to Iran? How did you go and how did you like it? I am seeing tours from Distant Horizons, Speikermann, Geo Ex, Serious Traveler/Travel Concepts International and Mir. I have read some rather negative reports about Eldertreks for other trips and am not too certain about Bestway either. I am somewhat concerned about the increased tensions and "sabre rattling" recently, which is why I do not want to wait until the Fall or next year. I do want a company that will be reliable and do it's utmost to protect it's travelers if anything does happen. I am not that interested in making my own arrangements and just going with a guide and me - my very small group experiences of 2 - 4 people and a guide have not been great - guides have been more interested in their friends than us travelers. But, I would consider it with excellent recommendations - anyone else interested in Iran? Thanks!