Let me preface that I like Spitfires, just not the 80HDs.
Like said in other posts, they're great of riding straight only, not carving, off high curbs, ledges, or even slappying anything.
In my initial setting them up, two of the cores literally couldn't hold my bearing – you flip it and the bearing just plopped out. Luckily, my local shop, had seen that problem and weren't afraid of popping open a new set and giving you the wheels that worked (they returned the set to DLX as faulty). Then once I had them working, I was at a pump track – a bit slippy on smooth concrete, but I attributed that to being new wheels. Leaving the track, I rolled off a tall curb on the way to the parking lot and a heard rattling. Another core busted and wouldn't hold the bearing in.
Went to my shop, again, and once again, they were great about switching out a wheel. I bought OJ Keyframes. I switched out the 80HDs to my wife's cruiser which strictly only rides on the smooth beach path. No problems since.
Put the Keyframes on my board and have been able to ride pools, cruise, and slappy curbs galore with no problems at all.