I took my first trip to Europe this summer, and I didn't know anyone who had flown Condor Air before. I was nervous because the carry on bag size was smaller, and I thought it might be akin to budget airline nightmares I've flown here in the states, but we decided to chance it, because the price and timing of the flight were much better than other options, and we even took a train from Munich on the day of travel to catch the Condor flight from Frankfurt because it allowed us a lazier morning, and a quicker return home, than the other options out of Munich.
While navigating the Frankfurt airport was a bit of a challenge (though this was our first international trip), we found the flight to be very accommodating for a nonstop flight from Frankfurt to Portland, OR. Even with a 45 min. delayed plane, they still made great time.
We flew Delta Comfort + on the way to Amsterdam, nonstop, and Premium Economy on Condor. We found the two flights to be comparable (though the food on Delta may have been a bit better -- one of us had vegan entrees, and the other just standard options), there was certainly no shortage of food offered on Condor). The flight attendants were nice and were available frequently throughout the flight. There was even a little footrest on the Condor flight (and do I mean little!)
We also booked "Rail & Fly" and we booked our train, and reserved seats, few days before the flight. TIP: RESERVE SEATS on Deutsche Bahn for long flights! You may be sitting under the luggage racks if you don't (yes, folks were sitting under the luggage racks!)
I would fly Condor again.