We should note that while the DC190 does not advertise compatibility with the iPhone, it did work during our testing. However, the phone will have to enter "airplane mode," as the DC190 lacks the proper shielding to allow the iPhone to operate normally.
The DC190 offers two separate alarm clocks, though they must share the same wake source. You can't have one alarm go off to the radio and the other to an iPod. That said, you can separately select the days of the week on which they go off. Additionally, you can manually set the maximum volume you'd like the speakers to reach. When an alarm goes off, the volume gradually increases until it matches your set level.
During our testing, we found that all the device's features performed well. Unfortunately, the same could not be said for the sound quality. It's tough to expect such a small package to sound great, but the DC190 didn't even sound average. Everything played out of the speakers is incredibly hollow, lacking any definition whatsoever. The FM radio fared a bit better, but we chalked that up to FM radio's already decreased source quality.
If you can get beyond the disappointing sound quality, the DC190 works as advertised and is affordable at $50. While we haven't heard the DC315 (it's due out in September), the $80 step-up properly supports iPhone playback and appears to have slightly larger speakers.
If you'd rather stray away from Philips altogether, iHome has two products we'd recommend. The iH41BR lingers in the $60 price range and offers a similar feature set (sans radio, but you get a remote) to the DC190, and the iP47BR gives you even more functionality, including iPhone shielding and Bluetooth capabilities.