There are little quirks I've never liked about iPhoto. It seems slow to respond, it makes extra copies of files. At one point you could put iPhoto on a diet, but you shouldn't need to download software to unbloat other software. Fortunately there are alternatives should you seek them out.
My favorite iPhoto alternative is Lightbox, which is the digital version of a pro photographer's physical lightbox. It organizes photos, similar to the iPhoto album structure, with support for most of the common RAW images flavors, as well as traditional compressed formats like JPG, PNG and TIF. One powerful feature of Lightbox is the ability to search by EXIF data. You can add custom meta data to files to further improve on search functionality. Backup support for tar.gz means nice neat compression for storing on DVD. iPhoto emulation mode allows you to use Lightbox in conjunction with iDVD and iMovie, instead of funneling photos through iPhoto. And to get you started, Lightbox imports photos from iPhoto so you can grow-up from the Apple-provided training wheels. Common tasks like DVD burning, HTML album creation, slideshows and format conversion also supported. [Mac OS X $25.00]
Another interesting option to replace both iPhoto and iTunes in Stimulus. Stimulus acts as an image browser with file sorting, while also providing a less bloated option than iTunes for playing back audio and video. Both slideshow and scale-to-fit display options make browsing images easy, image rotation and file details give you feedback on images. While Stimulus doesn't edit images, it does play well with others, supporting the ability to launch an external editor from within the Stimulus interface. There's also a Windows XP version. [Stimulus Windows XP / Mac OS X $19.95]
