Eric,
You are complaining about your Panasonic AJ-D400 cameras yet you are thinking about purchasing cameras that are MUCH MUCH WORSE then the AJ-D400.
I would seriously stay away from any handycam style camera (XL1, PD150 etc) to be used as a "primary tool" in any market size.
As for the JVC DV5000 or Pana AG200, they are a better choice due to their beta style lay out,
BIGGER CHIPS ease of control and lens options BUT unfortunately they only run in the CONSUMER DV mode, this is OK for an independent that feeds from the camera to his/her personal PC but this will run you into trouble feeding the raw tapes from deck to deck - you will have compatibility issues especially when feeding into DVCpro or DVcam decks due to the consumer DV slower speed and narrower track pitch. + they will probably break down even more often then the 400s you already have as they are even cheaper. (prosumer equals prosumer)
As another poster mentioned look for B STOCK sales. They (sony) may be dumping the DSR-300s / 370s for cheap because they are replacing them with the DSR-390. The DSR-300 is twice the camera compared to the AJ-D400 and even the AJ-D400 is 5 times the camera compared to the XL1.
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Here is the new DSR-390 should be available this month
http://bssc.sel.sony.com/NAB/category/products/dsr390.html
Here are some hi-lites (according to SONY marketing)
1) The DSR-390 camcorder will be available in May for a suggested list price of $9,870. with A new CCD sensor
2) The new DSR-390 DVCAM model delivers superb picture quality by utilizing the latest 1/2-inch Power HAD IT (ICX-418/419) 4:3 CCD sensors
3) The three-CCD array boosts sensitivity and S/N ratio while lowering vertical smear ratio. The new CCD's allow sensitivity levels to increase from F11 to F13 (about 3dB), S/N ratio increase by 3dB to 65dB, and smear ratio drops 5dB to an astounding "FIT like" level of -115dB.
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Good luck and please don't degrade your product to some third rate consumer shop, don't buy cheaper then the cams you already have, buy B STOCK or get the new SONY DSR-390s.
Notice I did not mention "BETACAM SP, SX, IMX or DIGI - not even once... 