I flew twice with Eurowings, first time London Heathrow to Hamburg, then Munich to London Stanstead. Both flights were about 20 mins late for takeoff and up to 45 minutes late for boarding. Not the end of the world, but it is worrying that Eurowings has consistently poor punctuality, particularly for a German carrier.
Once on the flights I was content with the overall experience for the price I paid, I am quite tall (195 cm) and booked the exit row both times. There was plenty of leg space and the seat was comfortable. The staff were polite and helpful and spoke both English and Deutsch. However, the wifi did not work and the snacks and drink on offer were not very nice. Also a warning that the flight attendants were actually checking the weight of some of the larger carry on bags so make sure yours are below the maximum carry on weight if you don't want to cop an additional charge.
In future, I would probably pay a bit more for the reliability and punctuality of a name brand airline. But if you are on a budget, have only a small amount of luggage, and are willing to risk some flight delays then Eurowings might be an ok choice.