Built and flown ARC PSR 1824 I think three times back in the day. Really cool to get the Korolev Cross action going! Takes some patience to build, especially sanding the interlock tabs to perfection after being painted. Mine got a little hibachied above the 24mm minimum diameter mount after three flights I would recommend a bit of reinforcement above that mount- CA soak or a coupler. Other than that carefully follow the instructions.
Good preparation and clustering techniques on 5 motors a must. Flies real high. Also a must is an assigned recovery team to recover all the falling bits from way above. Calm conditions to enjoy awesome K Cross Action. Will really impress even Top High Power Men! All that work for just a moment, then the moments gone...
They (ARC) went off ebay like 2010 ish, I have not seen one in years.
Parallel Staging is awesome.
Add on a D12 0 to the core for even more altitude junkie satisfaction and RSO frightening! Fly Loaded for Bear on the big, high power range!
PSR 1824...not for children!