Yes, they are tough.
I flew my P-51 into the ground - think lawn dart - and it survived incredibly well.
I was getting over-confident as it fly's so stable, and doing things a warbird shouldn't do like tight cornering and stall turns, which it does very well. Elevator throws were at full.
Well, I found her limits and she tipstalled from a very tight ( perhaps 6m diameter) turn into the famous P-51 spin about 20m up. I almost caught it but she tipstalled again and had to cut throttle 1 second before impact. She went in fast in a 80 degree dive. I was sure I was going to come back with confetti.
When I found it, it had broken a prop blade, and had slight wrinkles in the nose. Thats it!
On further inspection the motor mount was slightly loose, which needed the fuse cut open to re-glue. Looks like the spinner took the whole impact. I am impressed.
Oh, a good replacement prop is MAS 3 blade 11x7
I did a review of the Dynam Spitfire Here -> http://rcmodelairplanenews.tumblr.com/