Like most DSLRs the K-m starts up very quickly, and is ready to take a picture in well under a second. As I mentioned before, the AF system may be a bit uninformative but it is fast and accurate. Its low-light performance is also fairly good, but it requires the pop-up flash to be raised for its AF-assist strobe function to work, which means it's difficult to take low-light shots without the flash firing.
The camera's shooting speed is variable, depending on whether Raw mode is used or not. When shooting JPEG-only it can shoot at a constant two shots a second in single-shot mode, while in high-speed continuous mode it can shoot at up to three frames a second for about six or seven frames, before slowing down a little as the buffer fills up. It also has a low-speed continuous mode which maintains a constant 1.3fps.
Shooting single-shot in Raw mode, the K-m can average around one frame a second, although it does slow down noticeably after five frames, while in high-speed continuous it can fire a burst of four shots at 2fps, but then slows down to about one frame a second. In Raw+JPEG mode the high-speed burst is limited to only three frames. Most entry-level DSLRs have fairly limited performance, and there aren't many occasions when the small buffer will be a problem, but it is a limiting factor on the K-M's performance.
Finally we come to image quality, and here there is good news. When shooting in Raw mode the K-m produces sharp, perfectly exposed images with excellent natural colour reproduction, and is easily a match for any of its immediate rivals, and even for a couple of more expensive models. The SMC Pentax 18-55mm f/3.5 - 5.6 DAL lens may be getting on a bit, but it's still one of the best standard-zoom kit lenses on the market, with excellent corner-to-corner sharpness, and the minimal chromatic aberration that it produces is easily corrected in software.
In its default "Bright" setting, the JPEG mode is quite over-saturated, presumably to produce images more like those of a compact camera. Fortunately the menu includes a very good colour customisation system, and simply switching to the second pre-set "Natural" colour mode produces much better results.
Image noise is also very well handled, with good image quality up to 800 ISO, and usable images at 1600 ISO. Even 3200 ISO isn't a complete disaster, as long as you don't want to blow the pictures up too much.
The Pentax K-m is a good first camera. It has better build quality than most of its rivals, it handles and performs well, and is capable of producing excellent results even in the hands of a novice, while still having enough features and custom options to satisfy more experienced photographers. The only real problem is the annoying lack of AF target points in the viewfinder, which is both confusing and inconvenient.