I'm new to the forum, it's great to see these topics discussed.
And here's my disclaimer - for the last 5 years I have worked for an IP camera mfg, IQinVision. Megapixel, and recently multimegapixel cameras.
The posts claiming poor performance from the general IP cameras of
years past is correct. If you have an IP based back-end for recording,
(benefits well discussed in this thread) then you have an option of traditional CCTV cameras with an IP convertor or an IP camera. Generally, the CCTV
cameras with a convertor do offer more choices and lower prices.
That's why IQinVision focused on designing cameras that do things that
CCTV can't. Recently introduced: the IQeye602 does 1.3 megapixel progressive images at 30 images per second, and 2.0 megapixel images at 20 images per second. 640X480 at 60 images per second. True day/night, with .5 lux performance.
The IQeye3 was superseded with the new IQeye301 and 302. These cameras offers low light performance and digital pan tilt zoom, which is really neat. The camera is recording the whole field of view, while each user can pan tilt and zoom around in the image. If you have enough source resolution you can get reasonable zoom ratios before there is any quality degradation. Multiple users can be zoomed into different parts of the scene at the same time. Pan tilt zoom works in archived video too.
This year IIPSEC (the UK IP video surveillance tradeshow) awarded IQinVision Best of Show Hardware for their camera's ability to record their
own video on a normal corporate file server (via FTP). The reliability issue of recording on a PC with software is real - but recording to a highly reliable corporate server keeps the costs low and provides secure archival.
Sorry for the commercial - you guys are asking great questions and there is a lack of info out there, so I thought I'd register and post one insider's viewpoint. IP cameras have to outperform CCTV cameras to make sense. And the total solutions have to be less expensive. And the installers and specifiers have to make money. (you won't find our products over distributed like some)
Casinos, Homeland Security, Aerospace, Finance - anyone who wants state-of-the-art is using IQinVision. check them out in your explorations...