Wes,
Contact WEXLER VIDEO.
http://www.wexlervideo.com/
They are a rental house in Los Angeles and they are involved in many national REALITY TV programs, including SURVIVOR, FEAR FACTOR, THE REAL WORLD etc.
WEXLER VIDEO may be able to address your concerns as they have been assessing the IMX beta tape decks and cameras for 18 months prior to purchasing the gear two months ago. (total of 20 months of experience with IMX)
http://news.sel.sony.com/pressrelease/3355
As Dino mentioned, I would also recommend looking into SONY'S IMX BLUE LASER system. But be warned, at first, there may be major bugs in the system. CNN is about to assess the system any time now.
Just to be on the safe side, I would buy a few IMX BETA TAPE DECKS as well - you will need beta machines for your SP stock and IMX will play your SP tapes. I would also buy a few of the IMX beta tape camcorders. (just to be on the safe side) Or even a few of the cheaper SX camcorders, as they are also a MPEG-2 4:2:2 system and will play off the IMX studio decks.
Intergrading your IMX beta machines and your IMX blue laser machines will work fine as the signal will not have to be uncompressed/recompressed and will work with all IMX routers, IMX disk decks, IMX beta tape decks, IMX-servers, IMX switchers, and all other third party "IMX" hardware and software including NLEs.
I wouldn't completely write off TAPE just yet...
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Good luck and let us know what you decide.