At the risk of just spraying gasoline all over the place, I will state that my Cyclops sounded quite bombastic from the first moment it turned on. I never noticed any harshness, leanness, awfulness, or other annoying sonic artifacts. Also, my crops did not wither and die.
Two years on, it sounds just as bombastic, full-throated and scrumtrulescent as it did on day one. And for the record, it's on as long as the power company keeps the A/C on (don't even ask).
The subject of component break in is possibly secondary in contentiousness only to the hidden magical super powers of expensive cables, be they interconnects or speaker wire.
I know that Klaus has stated that his products benefit from a prolonged burn in period, I know Frank V.A. doesn't seem to have any use for burn in periods other than to bring his tube models up to proper operating temperature. I know that Jim Winey, the inventor of Magneplanars stated that you knew something was "right" the moment you first cut it on.
So what's a poor lad to believe, eh? I own something from all of the above individuals and I will be .... darned if I am going to argue with any of them. All three have excelled in their field and I pretty much am going to respect any opinions they hold, even if said opinions appear at first glance to directly contradict one another.
Based on my own personal experience, I observed the following:
Magneplanars - Absolutely perfect the moment they fired up for the first time (pretty much in accordance with what Mr Winey said).
Odyessey - Once again, perfection right out of the box, no detectable change in sound at 24, 48, or 2400 listening hours (not in accordance with Klaus's position).
Audio by Van Alstine - Not at all good (verging on awful) when it came out of the box, so I left the room and let the amp run with a CD on repeat for 3 or 4 hours. When I came back, it was all better and has been a perfect beast ever since, although I do give it about 20 minutes to come up to temperature before I do any "serious" listening (not in accordance with Frank's estimation of how things should work, and I will note that whereas I leave my Odyssey running 24/7, the AVA is powered off except when in use).
So make of that what you will. The above experiences apply to myself exclusively, your mileage may (and almost certainly will) vary.