I did a bit of testing of various cameras in $100 USD range...
Cameras I use are:
Dahua IPC-HDBW4300E (
http://sergei.nz/dahua-ipc-hdbw4300e/) Dome with 2.8mm lens for wider view, 1080p H264 High profile, short IR range.
Dahua IPC-HFW4300S (
http://sergei.nz/tag/ipc-hfw4300s/) Bullet with 3.6mm lens 1080p H264 High profile, medium IR range.
Hikvision DS-2CD2232-I5 (
http://sergei.nz/hikvision-ds-2cd2232-i5-12mm-lens/) Box with 12mm lens and very good IR range, 1080p H264 Main profile. This camera is useful for long driveways or number plate recognition.
Hikvision DS-2CD2032-I (
http://sergei.nz/hikvision-ds-2cd2032-i/) Bullet with 4mm lens, medium IR range, 1080p H264 Main profile. My second IP camera. I prefer Dahua IPC-HFW4300S over it (mostly subjective reasons).
Ubiquiti AIRCAM HD (
http://sergei.nz/ubiquiti-aircam-hd/) Bullet (?) with unknown lens (looks like 4mm) 720p H264 Main profile. No IR, crappy 24V PoE (not 802.3af/at). Pretty dated and old camera, image quality is crappy.
Camera I am going to test:
INC-MH40D06 2.8mm (
http://www.ildvr.com/products/inc-mh40d06). I should have it on my hands next week and going to import a few if it is similar or better to Dahua IPC-HDBW4300E.
Most of these cameras (Dahua and Hikvision) run Ambarella chip (very similar to GoPro Hero3).
Hikvision and Dahua are a bit of dicks when it comes to firmware (Dahua keeps their firmware secret, and Hikvision locks the language).
A bit of warning regarding Hikvision, even if your camera has English firmware initially if it has CH in the serial number, when you update the firmware it will revert to Chinese only (there are hacks floating on internet, but there is a risk of bricking).
My use case is not a standard so beware of my good experiences being not so good for you.
What I use these cameras for:
Pure RTSP stream: I use two streams from each camera, low res. for motion detection and high res. for capture.
I don't use any inbuilt motion detection or zoning, neither I use DVRs or ONVIF compatible storage products (eg.: synology).
I wrote my own motion detection, zoning and capturing software (using python opencv libraries).
All I care about in the cameras is stable RTSP stream and good image quality.