We bought (through the internet) 2 Radon hardtail bikes, one MTB 29 for me, and one 26 for my partner.
Bikes (both) are excellent. Problems that I've had:
Pedals, they could be better. They broke and I asked for a replacement. They provided the same pedals for free. After few months the same symptoms, but for now I am still using them since it is not dramatic. I understand that it will be solved when I buy better pedals.
Gears, at the highest position the chain touches the mechanism. I have to adjust (yet)
My partner's bike, no problems. At the price offered, this is a must-buy (unless you don't care for 200€ of difference).
From a visual point of view, I was expecting something just more ugly than the (my) reference Cube. Based on the photos, that was clear. Once in person, they are way more beautiful than what I was expecting.
Conclusion: If I was buying another bike now? With my budget, Radon without any doubt. With a bigger budget? I don't know. I have no reasons to move from Radon. I would have more problems in deciding between a 26 and a 29 than deciding about a
About sizes: I followed the indications of Radon webpage. No problems with that. It is true that I "think" that the size is the correct one. I could be with a wrong one and since I cannot compare with a previous MTB, I don't know. So far, it seems to fit without problems.