We set up a Dropcam Echo in a house and were generally impressed with the video and sound quality (which we were accessing remotely, from about 100 miles away). While you can't blow the onscreen image up too much without it pixelating, at native size it looks sharp and the exposure was good, though the Dropcam can't compensate for abundant light (the sun shining directly at it). It also acquits itself fairly well in low light, though it can't do anything with total darkness.
In our video tests, we remotely watched a closed patio umbrella and trees blowing in the wind. While the video wasn't always buttery smooth (the Webcam is supposed to capture at 30 frames per second but that may vary with our Web connection), it was smooth enough.
One of the key things to note is that basic "live" video monitoring is included as part of the purchase of a Dropcam, free of charge. That allows you to view live video over the Internet at Dropcam.com or stream video to your iPhone using the free Dropcam app, which also worked well. (Note: there's no word on an Android app at this time, but we hope the Dropcam folks take that logical next step.)
To use Dropcam's DVR functionality, you have to upgrade to one of the paid services, which start at $8.95 a month per camera for the Plus Plan. The Plus plan gives seven days of online recording on Dropcam's secure servers. That means you can go back a week to view anything you might have missed. In addition, you can download screenshots or video clips to archive footage permanently and opt to get e-mail alerts when any movement is detected. (As always, the presence of a cat or dog in the home will play havoc with your motion-triggered alerts.) The $24.95 Pro Plan (also per camera) ups that to 30 days of recording.
One major competitor to Dropcam is the Logitech Alert consumer video security system. The one advantage the Logitech system has is its cameras offer higher-resolution video. However, its system uses Powerline adapters instead of Wi-Fi to tap into your home network (you use your home's power outlets to interface with hardwired Ethernet connections). While that usually works well in newer homes, Powerline doesn't work in many older homes that have dated wiring.
All in all, we really liked what the Dropcam system offers and have no problem recommending it to anyone who has a Wi-Fi network in place. Yes, the cameras are a bit on the expensive side at $200 and $280 respectively, but they're competitively priced (for security cameras) and cost less than the aforementioned Logitech system.