Currently, I use DSR250's to record long seminars. They hold 3 hour tapes and make it very convenient to record long programs. The DSR250's are starting to show their wear and tear. What new prosumer or broadcast cameras are available to record long form programs? Maybe a camera that records both SD and HD? Also, does anyone know of a good repair shop for the 250's in Chicago? And, if not in Chicago, where?
People tend to think of "flash == small" and "tape/HDD = large", but that's kind of old thinking. A 63 minute DV tape stores 12GB, an 83 minute DV tape stores 16GB... not huge.
Most AVC camcorders record at 24Mb/s or less, at their peak bitrate. That's under 11GB per hour. So you get almost 3 hours on a 32GB SDHC card. In practice, you may actually get more than 3 hours, particularly shooting a low-motion subject such as a seminar. Most tapeless cameras record in variable bitrate.
And of course, they all offer lower average bitrate modes as well. So for a hit in overall quality, you can get close to six hours on the same memory card.
Some consumer models also support more than 32GB of internal flash memory, or, as you mentioned, hard drives. I'm not a fan of HDD models, as the HDD then becomes the most fragile part of the camera, and they may simply not work at high altitudes. If your camera supports the SDXC card standard, you can currently buy 64GB memory cards, which would give you around six hours of shooting at top quality.
And by "top quality", I mean high definition. You're currently shooting in DVCAM on full size tapes (4.5 hours max)... you can definitely get something similar onto a memory card. Maybe HD doesn't even matter... that's something to check on the spec sheets -- many HD models don't do SD, but you might be happy with 720p rather than 1080i.